diff --git a/apps/platform/app/Filament/Resources/ProviderConnectionResource.php b/apps/platform/app/Filament/Resources/ProviderConnectionResource.php
index a47b1de7..e18fcdaf 100644
--- a/apps/platform/app/Filament/Resources/ProviderConnectionResource.php
+++ b/apps/platform/app/Filament/Resources/ProviderConnectionResource.php
@@ -21,8 +21,8 @@
 use App\Support\Badges\BadgeRenderer;
 use App\Support\Filament\TablePaginationProfiles;
 use App\Support\ManagedEnvironmentLinks;
-use App\Support\Navigation\WorkspaceHubNavigation;
 use App\Support\Navigation\WorkspaceHubEnvironmentFilter;
+use App\Support\Navigation\WorkspaceHubNavigation;
 use App\Support\OperationRunLinks;
 use App\Support\OperationRunType;
 use App\Support\OpsUx\OpsUxBrowserEvents;
@@ -270,6 +270,12 @@ private static function resolveTenantExternalIdFromLivewireRequest(): ?string
             // Ignore and fall back to referer.
         }
 
+        $externalId = static::extractTenantExternalIdFromLivewireSnapshot();
+
+        if (is_string($externalId) && $externalId !== '') {
+            return $externalId;
+        }
+
         $referer = request()->headers->get('referer');
 
         if (! is_string($referer) || $referer === '') {
@@ -279,6 +285,56 @@ private static function resolveTenantExternalIdFromLivewireRequest(): ?string
         return static::extractTenantExternalIdFromUrl($referer);
     }
 
+    private static function extractTenantExternalIdFromLivewireSnapshot(): ?string
+    {
+        $snapshotJson = request()->input('components.0.snapshot');
+
+        if (! is_string($snapshotJson) || $snapshotJson === '') {
+            return null;
+        }
+
+        $snapshot = json_decode($snapshotJson, true);
+
+        if (! is_array($snapshot)) {
+            return null;
+        }
+
+        $componentName = data_get($snapshot, 'memo.name');
+
+        if (! is_string($componentName) || $componentName !== Pages\CreateProviderConnection::class) {
+            return null;
+        }
+
+        $environmentId = data_get($snapshot, 'data.environmentId');
+
+        if (is_array($environmentId) || filter_var($environmentId, FILTER_VALIDATE_INT) === false) {
+            return null;
+        }
+
+        $workspaceId = app(WorkspaceContext::class)->currentWorkspaceId(request());
+
+        if (! is_int($workspaceId)) {
+            return null;
+        }
+
+        $tenant = ManagedEnvironment::query()
+            ->whereKey((int) $environmentId)
+            ->where('workspace_id', $workspaceId)
+            ->first();
+
+        if (! $tenant instanceof ManagedEnvironment) {
+            return null;
+        }
+
+        $user = request()->user();
+
+        if ($user instanceof User && ! $user->canAccessTenant($tenant)) {
+            return null;
+        }
+
+        return (string) $tenant->slug;
+    }
+
     private static function extractTenantExternalIdFromUrl(string $url): ?string
     {
         $query = parse_url($url, PHP_URL_QUERY);
@@ -341,14 +397,6 @@ private static function applyMembershipScope(Builder $query): Builder
         $workspaceId = app(WorkspaceContext::class)->currentWorkspaceId(request());
         $user = auth()->user();
 
-        if (! is_int($workspaceId)) {
-            $tenant = static::resolveTenantContextForCurrentPanel();
-
-            if ($tenant instanceof ManagedEnvironment) {
-                $workspaceId = (int) $tenant->workspace_id;
-            }
-        }
-
         if (! is_int($workspaceId) || ! $user instanceof User) {
             return $query->whereRaw('1 = 0');
         }
diff --git a/apps/platform/app/Filament/Resources/ProviderConnectionResource/Pages/CreateProviderConnection.php b/apps/platform/app/Filament/Resources/ProviderConnectionResource/Pages/CreateProviderConnection.php
index 0805ef04..d82bf5c6 100644
--- a/apps/platform/app/Filament/Resources/ProviderConnectionResource/Pages/CreateProviderConnection.php
+++ b/apps/platform/app/Filament/Resources/ProviderConnectionResource/Pages/CreateProviderConnection.php
@@ -9,19 +9,34 @@
 use App\Support\Providers\ProviderConnectionType;
 use App\Support\Providers\ProviderConsentStatus;
 use App\Support\Providers\ProviderReasonCodes;
+use App\Support\Providers\ProviderVerificationStatus;
 use App\Support\Providers\TargetScope\ProviderConnectionTargetScopeDescriptor;
 use App\Support\Providers\TargetScope\ProviderConnectionTargetScopeNormalizer;
-use App\Support\Providers\ProviderVerificationStatus;
 use Filament\Notifications\Notification;
 use Filament\Resources\Pages\CreateRecord;
 use Illuminate\Validation\ValidationException;
+use Livewire\Attributes\Locked;
 
 class CreateProviderConnection extends CreateRecord
 {
     protected static string $resource = ProviderConnectionResource::class;
 
+    #[Locked]
+    public ?int $environmentId = null;
+
     protected bool $shouldMakeDefault = false;
 
+    public function mount(): void
+    {
+        $environmentId = request()->query('environment_id');
+
+        if (! is_array($environmentId) && filter_var($environmentId, FILTER_VALIDATE_INT) !== false) {
+            $this->environmentId = (int) $environmentId;
+        }
+
+        parent::mount();
+    }
+
     protected function mutateFormDataBeforeCreate(array $data): array
     {
         $tenant = $this->currentTenant();
diff --git a/apps/platform/app/Policies/ProviderConnectionPolicy.php b/apps/platform/app/Policies/ProviderConnectionPolicy.php
index d06a4c8b..7bfbf9f7 100644
--- a/apps/platform/app/Policies/ProviderConnectionPolicy.php
+++ b/apps/platform/app/Policies/ProviderConnectionPolicy.php
@@ -9,10 +9,10 @@
 use App\Services\Auth\ManagedEnvironmentAccessScopeResolver;
 use App\Support\Auth\Capabilities;
 use App\Support\Workspaces\WorkspaceContext;
-use Filament\Facades\Filament;
 use Illuminate\Auth\Access\HandlesAuthorization;
 use Illuminate\Auth\Access\Response;
 use Illuminate\Support\Facades\Gate;
+use Livewire\Livewire as LivewireFacade;
 
 class ProviderConnectionPolicy
 {
@@ -210,14 +210,6 @@ private function currentWorkspace(User $user): ?Workspace
     {
         $workspaceId = app(WorkspaceContext::class)->currentWorkspaceId(request());
 
-        if (! is_int($workspaceId)) {
-            $filamentTenant = Filament::getTenant();
-
-            if ($filamentTenant instanceof ManagedEnvironment) {
-                $workspaceId = (int) $filamentTenant->workspace_id;
-            }
-        }
-
         if (! is_int($workspaceId)) {
             return null;
         }
@@ -237,33 +229,117 @@ private function currentWorkspace(User $user): ?Workspace
 
     private function resolveCreateTenant(Workspace $workspace): ?ManagedEnvironment
     {
-        $requestedEnvironmentId = request()->query('environment_id');
-
-        if (! is_numeric($requestedEnvironmentId)) {
-            $lastEnvironmentId = app(WorkspaceContext::class)->lastEnvironmentId(request());
-
-            if (is_int($lastEnvironmentId)) {
-                return ManagedEnvironment::query()
-                    ->whereKey($lastEnvironmentId)
-                    ->where('workspace_id', (int) $workspace->getKey())
-                    ->first();
-            }
-
-            $filamentTenant = Filament::getTenant();
-
-            if ($filamentTenant instanceof ManagedEnvironment && (int) $filamentTenant->workspace_id === (int) $workspace->getKey()) {
-                return $filamentTenant;
-            }
+        $requestedEnvironmentId = $this->requestedEnvironmentId();
 
+        if ($requestedEnvironmentId === null) {
             return null;
         }
 
         return ManagedEnvironment::query()
-            ->whereKey((int) $requestedEnvironmentId)
+            ->whereKey($requestedEnvironmentId)
             ->where('workspace_id', (int) $workspace->getKey())
             ->first();
     }
 
+    private function requestedEnvironmentId(): ?int
+    {
+        $environmentId = request()->query('environment_id');
+
+        if (is_numeric($environmentId)) {
+            return (int) $environmentId;
+        }
+
+        if (is_array($environmentId)) {
+            return null;
+        }
+
+        try {
+            $resolved = $this->extractEnvironmentIdFromLivewireSnapshot();
+
+            if ($resolved !== null) {
+                return $resolved;
+            }
+        } catch (\Throwable) {
+            // Ignore and fall back to originalUrl() parsing.
+        }
+
+        try {
+            $url = LivewireFacade::originalUrl();
+
+            $resolved = $this->extractEnvironmentIdFromUrl($url);
+
+            if ($resolved !== null) {
+                return $resolved;
+            }
+        } catch (\Throwable) {
+            // Ignore and fall back to referer header.
+        }
+
+        $referer = request()->headers->get('referer');
+
+        if (! is_string($referer) || $referer === '') {
+            return null;
+        }
+
+        return $this->extractEnvironmentIdFromUrl($referer);
+    }
+
+    private function extractEnvironmentIdFromLivewireSnapshot(): ?int
+    {
+        if (! request()->headers->has('x-livewire') && ! request()->headers->has('x-livewire-navigate')) {
+            return null;
+        }
+
+        $snapshotJson = request()->input('components.0.snapshot');
+
+        if (! is_string($snapshotJson) || $snapshotJson === '') {
+            return null;
+        }
+
+        $snapshot = json_decode($snapshotJson, true);
+
+        if (! is_array($snapshot)) {
+            return null;
+        }
+
+        $componentName = data_get($snapshot, 'memo.name');
+
+        if (! is_string($componentName) || $componentName !== \App\Filament\Resources\ProviderConnectionResource\Pages\CreateProviderConnection::class) {
+            return null;
+        }
+
+        $environmentId = data_get($snapshot, 'data.environmentId');
+
+        if (is_array($environmentId) || filter_var($environmentId, FILTER_VALIDATE_INT) === false) {
+            return null;
+        }
+
+        return (int) $environmentId;
+    }
+
+    private function extractEnvironmentIdFromUrl(?string $url): ?int
+    {
+        if (! is_string($url) || $url === '') {
+            return null;
+        }
+
+        $query = parse_url($url, PHP_URL_QUERY);
+
+        if (! is_string($query) || $query === '') {
+            return null;
+        }
+
+        parse_str($query, $params);
+
+        $environmentId = $params['environment_id'] ?? null;
+
+        if (is_array($environmentId) || filter_var($environmentId, FILTER_VALIDATE_INT) === false) {
+            return null;
+        }
+
+        return (int) $environmentId;
+    }
+
     private function tenantForConnection(ProviderConnection $connection): ?ManagedEnvironment
     {
         if ($connection->relationLoaded('tenant') && $connection->tenant instanceof ManagedEnvironment) {
diff --git a/apps/platform/tests/Feature/Audit/ProviderConnectionIdentityAuditTest.php b/apps/platform/tests/Feature/Audit/ProviderConnectionIdentityAuditTest.php
index c528f83f..678625d8 100644
--- a/apps/platform/tests/Feature/Audit/ProviderConnectionIdentityAuditTest.php
+++ b/apps/platform/tests/Feature/Audit/ProviderConnectionIdentityAuditTest.php
@@ -4,8 +4,8 @@
 
 use App\Filament\Resources\ProviderConnectionResource\Pages\CreateProviderConnection;
 use App\Models\AuditLog;
-use App\Models\ProviderConnection;
 use App\Models\ManagedEnvironment;
+use App\Models\ProviderConnection;
 use App\Models\User;
 use Filament\Facades\Filament;
 use Illuminate\Foundation\Testing\RefreshDatabase;
@@ -76,6 +76,9 @@
     Filament::setTenant($tenant, true);
 
     Livewire::actingAs($user)
+        ->withQueryParams([
+            'environment_id' => (int) $tenant->getKey(),
+        ])
         ->test(CreateProviderConnection::class)
         ->fillForm([
             'display_name' => 'Audit target scope connection',
diff --git a/apps/platform/tests/Feature/ProviderConnections/MvpProviderScopeTest.php b/apps/platform/tests/Feature/ProviderConnections/MvpProviderScopeTest.php
index c72a585f..6ab3f9c5 100644
--- a/apps/platform/tests/Feature/ProviderConnections/MvpProviderScopeTest.php
+++ b/apps/platform/tests/Feature/ProviderConnections/MvpProviderScopeTest.php
@@ -15,7 +15,11 @@
     $tenant->makeCurrent();
     Filament::setTenant($tenant, true);
 
-    Livewire::test(CreateProviderConnection::class)
+    $component = Livewire::withQueryParams([
+        'environment_id' => (int) $tenant->getKey(),
+    ])->test(CreateProviderConnection::class);
+
+    $component
         ->fillForm([
             'display_name' => 'MVP Scope Connection',
             'entra_tenant_id' => (string) fake()->uuid(),
diff --git a/apps/platform/tests/Feature/ProviderConnections/ProviderConnectionNeutralitySpec238Test.php b/apps/platform/tests/Feature/ProviderConnections/ProviderConnectionNeutralitySpec238Test.php
index fe697eed..eb79743b 100644
--- a/apps/platform/tests/Feature/ProviderConnections/ProviderConnectionNeutralitySpec238Test.php
+++ b/apps/platform/tests/Feature/ProviderConnections/ProviderConnectionNeutralitySpec238Test.php
@@ -81,6 +81,9 @@
     Filament::setTenant($tenant, true);
 
     Livewire::actingAs($user)
+        ->withQueryParams([
+            'environment_id' => (int) $tenant->getKey(),
+        ])
         ->test(CreateProviderConnection::class)
         ->fillForm([
             'display_name' => 'Missing target scope',
diff --git a/apps/platform/tests/Feature/ProviderConnections/ScopeHardeningAuthoritySourcesTest.php b/apps/platform/tests/Feature/ProviderConnections/ScopeHardeningAuthoritySourcesTest.php
new file mode 100644
index 00000000..eb137bca
--- /dev/null
+++ b/apps/platform/tests/Feature/ProviderConnections/ScopeHardeningAuthoritySourcesTest.php
@@ -0,0 +1,197 @@
+<?php
+
+declare(strict_types=1);
+
+use App\Models\ManagedEnvironment;
+use App\Models\Workspace;
+use App\Policies\ProviderConnectionPolicy;
+use App\Support\Workspaces\WorkspaceContext;
+use Filament\Facades\Filament;
+use Illuminate\Auth\Access\Response;
+use Illuminate\Http\Request;
+
+it('ScopeHardening requires explicit environment_id for ProviderConnectionPolicy::create even if a remembered environment exists', function (): void {
+    $environment = ManagedEnvironment::factory()->active()->create([
+        'external_id' => 'spec339-scopehardening-env-remembered',
+    ]);
+
+    [$user, $environment] = createUserWithTenant(tenant: $environment, role: 'owner');
+
+    $this->actingAs($user);
+    session()->put(WorkspaceContext::SESSION_KEY, (int) $environment->workspace_id);
+    session()->put(WorkspaceContext::LAST_ENVIRONMENT_IDS_SESSION_KEY, [
+        (string) $environment->workspace_id => (int) $environment->getKey(),
+    ]);
+
+    /** @var ProviderConnectionPolicy $policy */
+    $policy = app(ProviderConnectionPolicy::class);
+
+    $result = $policy->create($user);
+
+    expect($result)->toBeInstanceOf(Response::class);
+    expect($result->denied())->toBeTrue();
+});
+
+it('ScopeHardening requires explicit environment_id for ProviderConnectionPolicy::create even if Filament tenant is set', function (): void {
+    $environment = ManagedEnvironment::factory()->active()->create([
+        'external_id' => 'spec339-scopehardening-env-filament',
+    ]);
+
+    [$user, $environment] = createUserWithTenant(tenant: $environment, role: 'owner');
+
+    Filament::setTenant($environment, true);
+
+    $this->actingAs($user);
+    session()->put(WorkspaceContext::SESSION_KEY, (int) $environment->workspace_id);
+
+    /** @var ProviderConnectionPolicy $policy */
+    $policy = app(ProviderConnectionPolicy::class);
+
+    $result = $policy->create($user);
+
+    expect($result)->toBeInstanceOf(Response::class);
+    expect($result->denied())->toBeTrue();
+});
+
+it('ScopeHardening ignores legacy query aliases for ProviderConnectionPolicy::create authority', function (): void {
+    $environment = ManagedEnvironment::factory()->active()->create([
+        'external_id' => 'spec339-scopehardening-env-alias',
+    ]);
+
+    [$user, $environment] = createUserWithTenant(tenant: $environment, role: 'owner');
+
+    $request = Request::create('/admin/provider-connections/create', 'GET', [
+        'managed_environment_id' => (int) $environment->getKey(),
+    ]);
+
+    $this->app->instance('request', $request);
+
+    $this->actingAs($user);
+    session()->put(WorkspaceContext::SESSION_KEY, (int) $environment->workspace_id);
+    session()->put(WorkspaceContext::LAST_ENVIRONMENT_IDS_SESSION_KEY, [
+        (string) $environment->workspace_id => (int) $environment->getKey(),
+    ]);
+
+    /** @var ProviderConnectionPolicy $policy */
+    $policy = app(ProviderConnectionPolicy::class);
+
+    $result = $policy->create($user);
+
+    expect($result)->toBeInstanceOf(Response::class);
+    expect($result->denied())->toBeTrue();
+});
+
+it('ScopeHardening denies ProviderConnectionPolicy::create for environment_id that belongs to another workspace', function (): void {
+    $environmentA = ManagedEnvironment::factory()->active()->create([
+        'external_id' => 'spec339-scopehardening-env-a',
+    ]);
+    [$user, $environmentA] = createUserWithTenant(tenant: $environmentA, role: 'owner');
+
+    $workspaceB = Workspace::factory()->create();
+    $environmentB = ManagedEnvironment::factory()->active()->create([
+        'workspace_id' => (int) $workspaceB->getKey(),
+        'external_id' => 'spec339-scopehardening-env-b',
+    ]);
+
+    $request = Request::create('/admin/provider-connections/create', 'GET', [
+        'environment_id' => (int) $environmentB->getKey(),
+    ]);
+
+    $this->app->instance('request', $request);
+
+    $this->actingAs($user);
+    session()->put(WorkspaceContext::SESSION_KEY, (int) $environmentA->workspace_id);
+
+    /** @var ProviderConnectionPolicy $policy */
+    $policy = app(ProviderConnectionPolicy::class);
+
+    $result = $policy->create($user);
+
+    expect($result)->toBeInstanceOf(Response::class);
+    expect($result->denied())->toBeTrue();
+});
+
+it('ScopeHardening returns 403 (not 404) for the create page when environment_id is missing (UI entry behavior)', function (): void {
+    $environment = ManagedEnvironment::factory()->active()->create([
+        'external_id' => 'spec339-scopehardening-create-page',
+    ]);
+
+    [$user, $environment] = createUserWithTenant(tenant: $environment, role: 'owner');
+
+    $this->actingAs($user)
+        ->withSession([
+            WorkspaceContext::SESSION_KEY => (int) $environment->workspace_id,
+        ])
+        ->get('/admin/provider-connections/create')
+        ->assertForbidden();
+});
+
+it('ScopeHardening returns 404 for the create page when environment_id belongs to another workspace (UI entry behavior)', function (): void {
+    $environmentA = ManagedEnvironment::factory()->active()->create([
+        'external_id' => 'spec339-scopehardening-create-page-a',
+    ]);
+    [$user, $environmentA] = createUserWithTenant(tenant: $environmentA, role: 'owner');
+
+    $workspaceB = Workspace::factory()->create();
+    $environmentB = ManagedEnvironment::factory()->active()->create([
+        'workspace_id' => (int) $workspaceB->getKey(),
+        'external_id' => 'spec339-scopehardening-create-page-b',
+    ]);
+
+    $this->actingAs($user)
+        ->withSession([
+            WorkspaceContext::SESSION_KEY => (int) $environmentA->workspace_id,
+        ])
+        ->get('/admin/provider-connections/create?environment_id='.(int) $environmentB->getKey())
+        ->assertNotFound();
+});
+
+it('ScopeHardening returns 403 (not 404) for the create page when legacy alias is provided (UI entry behavior)', function (): void {
+    $environment = ManagedEnvironment::factory()->active()->create([
+        'external_id' => 'spec339-scopehardening-create-page-alias',
+    ]);
+
+    [$user, $environment] = createUserWithTenant(tenant: $environment, role: 'owner');
+
+    $this->actingAs($user)
+        ->withSession([
+            WorkspaceContext::SESSION_KEY => (int) $environment->workspace_id,
+        ])
+        ->get('/admin/provider-connections/create?managed_environment_id='.(int) $environment->getKey())
+        ->assertForbidden();
+});
+
+it('ScopeHardening returns 403 (not 404) for the create page even if a remembered environment exists (UI entry behavior)', function (): void {
+    $environment = ManagedEnvironment::factory()->active()->create([
+        'external_id' => 'spec339-scopehardening-create-page-remembered',
+    ]);
+
+    [$user, $environment] = createUserWithTenant(tenant: $environment, role: 'owner');
+
+    $this->actingAs($user)
+        ->withSession([
+            WorkspaceContext::SESSION_KEY => (int) $environment->workspace_id,
+            WorkspaceContext::LAST_ENVIRONMENT_IDS_SESSION_KEY => [
+                (string) $environment->workspace_id => (int) $environment->getKey(),
+            ],
+        ])
+        ->get('/admin/provider-connections/create')
+        ->assertForbidden();
+});
+
+it('ScopeHardening returns 403 (not 404) for the create page even if Filament tenant is set (UI entry behavior)', function (): void {
+    $environment = ManagedEnvironment::factory()->active()->create([
+        'external_id' => 'spec339-scopehardening-create-page-filament',
+    ]);
+
+    [$user, $environment] = createUserWithTenant(tenant: $environment, role: 'owner');
+
+    Filament::setTenant($environment, true);
+
+    $this->actingAs($user)
+        ->withSession([
+            WorkspaceContext::SESSION_KEY => (int) $environment->workspace_id,
+        ])
+        ->get('/admin/provider-connections/create')
+        ->assertForbidden();
+});
diff --git a/apps/platform/tests/Feature/ProviderConnections/ScopeHardeningPolicyWorkspaceAuthorityTest.php b/apps/platform/tests/Feature/ProviderConnections/ScopeHardeningPolicyWorkspaceAuthorityTest.php
new file mode 100644
index 00000000..c91f5876
--- /dev/null
+++ b/apps/platform/tests/Feature/ProviderConnections/ScopeHardeningPolicyWorkspaceAuthorityTest.php
@@ -0,0 +1,32 @@
+<?php
+
+declare(strict_types=1);
+
+use App\Models\ManagedEnvironment;
+use App\Models\User;
+use App\Policies\ProviderConnectionPolicy;
+use App\Support\Workspaces\WorkspaceContext;
+use Filament\Facades\Filament;
+use Illuminate\Auth\Access\Response;
+
+it('ScopeHardening does not derive workspace authority from Filament tenant in ProviderConnectionPolicy', function (): void {
+    $environment = ManagedEnvironment::factory()->active()->create([
+        'external_id' => 'spec339-scopehardening-policy-env',
+    ]);
+
+    [$user, $environment] = createUserWithTenant(tenant: $environment, role: 'owner');
+
+    expect($user)->toBeInstanceOf(User::class);
+
+    session()->forget(WorkspaceContext::SESSION_KEY);
+
+    Filament::setTenant($environment, true);
+
+    /** @var ProviderConnectionPolicy $policy */
+    $policy = app(ProviderConnectionPolicy::class);
+
+    $result = $policy->viewAny($user);
+
+    expect($result)->toBeInstanceOf(Response::class);
+    expect($result->denied())->toBeTrue();
+});
diff --git a/apps/platform/tests/Feature/ProviderConnections/ScopeHardeningResourceWorkspaceAuthorityTest.php b/apps/platform/tests/Feature/ProviderConnections/ScopeHardeningResourceWorkspaceAuthorityTest.php
new file mode 100644
index 00000000..e4b88163
--- /dev/null
+++ b/apps/platform/tests/Feature/ProviderConnections/ScopeHardeningResourceWorkspaceAuthorityTest.php
@@ -0,0 +1,35 @@
+<?php
+
+declare(strict_types=1);
+
+use App\Filament\Resources\ProviderConnectionResource\Pages\ListProviderConnections;
+use App\Models\ManagedEnvironment;
+use App\Models\ProviderConnection;
+use App\Support\Workspaces\WorkspaceContext;
+use Filament\Facades\Filament;
+use Livewire\Livewire;
+
+it('ScopeHardening does not infer provider connection list workspace from Filament tenant when no workspace is selected', function (): void {
+    $environment = ManagedEnvironment::factory()->active()->create([
+        'external_id' => 'spec339-scopehardening-resource-env',
+    ]);
+
+    [$user, $environment] = createUserWithTenant(tenant: $environment, role: 'owner');
+
+    $connection = ProviderConnection::factory()->create([
+        'workspace_id' => (int) $environment->workspace_id,
+        'managed_environment_id' => (int) $environment->getKey(),
+        'display_name' => 'Spec339 ScopeHardening Connection',
+        'provider' => 'microsoft',
+    ]);
+
+    $this->actingAs($user);
+
+    session()->forget(WorkspaceContext::SESSION_KEY);
+
+    Filament::setTenant($environment, true);
+
+    $component = Livewire::test(ListProviderConnections::class);
+
+    expect($component->instance())->toBeNull();
+});
diff --git a/specs/339-provider-connection-scope-hardening/plan.md b/specs/339-provider-connection-scope-hardening/plan.md
new file mode 100644
index 00000000..ae8e30a1
--- /dev/null
+++ b/specs/339-provider-connection-scope-hardening/plan.md
@@ -0,0 +1,314 @@
+# Implementation Plan: Spec 339 - Provider Connection Scope Hardening
+
+- Branch: `339-provider-connection-scope-hardening`
+- Date: 2026-05-31
+- Spec: `specs/339-provider-connection-scope-hardening/spec.md`
+- Input: Spec 339 + repo inspection of Provider Connection policy/resource authority seams.
+
+## Summary
+
+Harden Provider Connections (credential-adjacent) so that authorization and scope authority come only from:
+
+- explicit workspace context (`WorkspaceContext`, session),
+- explicit `environment_id` (filter/create), or
+- record ownership (workspace + managed environment) for view/edit/actions.
+
+Remove hidden fallbacks (remembered environment and Filament tenant) as authority sources and guard the contract with targeted tests.
+
+## Technical Context
+
+- Language/Version: PHP 8.4.15, Laravel 12.52.x.
+- Primary Dependencies: Filament 5.x, Livewire 4.x, Pest 4.x.
+- Storage: PostgreSQL; no schema change expected.
+- Testing: Pest Feature tests (ProviderConnections family).
+- Validation Lanes: fast-feedback (Feature). Browser smoke only if visible UX changes are introduced.
+- Target Platform: Sail locally; Dokploy/container posture unchanged.
+- Project Type: Laravel monolith under `apps/platform`.
+- Constraints: no new persisted truth, migrations, packages, or broad navigation redesign.
+
+## UI / Surface Guardrail Plan
+
+- **Guardrail scope**: existing operator-facing resource + credential-adjacent action gating (authority hardening).
+- **Affected surfaces**:
+  - Provider Connections list/view/create/edit routes (`/admin/provider-connections*`).
+  - Create CTA availability and create authorization (must require explicit `environment_id`).
+  - Policy semantics (404 vs 403) and record-derived authority for actions.
+- **Native vs custom**: native Filament + existing capability/policy seams; no custom UI framework.
+- **Shared-family relevance**: workspace hub filter contract, authorization semantics, action-surface discipline for credential-adjacent actions.
+- **State layers in scope**: URL query (`environment_id` only), session workspace context, record ownership.
+- **Handling modes**: review-mandatory (security semantics).
+- **Required tests / smoke**:
+  - Feature tests that prove forbidden fallbacks cannot authorize create/view/actions.
+  - Optional reuse of existing browser smoke only if UI copy/CTA visibility changes are required.
+- **UI/Productization coverage**: no new surface; do not update UI audit coverage files unless navigation routes change.
+
+## Shared Pattern & System Fit
+
+- **Cross-cutting feature marker**: yes.
+- **Systems touched (expected)**:
+  - `apps/platform/app/Policies/ProviderConnectionPolicy.php`
+  - `apps/platform/app/Filament/Resources/ProviderConnectionResource.php`
+  - `apps/platform/app/Support/Workspaces/WorkspaceContext.php`
+  - `apps/platform/app/Support/Navigation/WorkspaceHubEnvironmentFilter.php`
+  - `apps/platform/tests/Feature/ProviderConnections/*`
+- **Shared abstractions reused**: `WorkspaceContext`, deny-as-not-found semantics, capability resolver and gates, existing ProviderConnections test family.
+- **New abstraction introduced?**: none.
+- **Bounded deviation / spread control**: do not introduce a new “scope resolver framework”; keep changes local to the ProviderConnection policy/resource seams.
+
+## OperationRun UX Impact
+
+No new `OperationRun` types or start UX changes.
+
+Provider operations reachable from Provider Connections must remain scoped to the record’s owning environment/workspace, but this spec’s changes should be limited to authority and authorization guardrails.
+
+## Implementation Approach
+
+### Phase 1 — Repo truth + failing tests first
+
+- Inventory the current forbidden fallbacks:
+  - `ProviderConnectionPolicy::currentWorkspace()` fallback to `Filament::getTenant()`.
+  - `ProviderConnectionPolicy::resolveCreateTenant()` fallback to `WorkspaceContext::lastEnvironmentId()` and `Filament::getTenant()`.
+  - Provider Connection resource query scoping fallback paths when workspace context is missing.
+- Add failing tests proving:
+  - create is impossible without explicit `environment_id` (even if remembered environment exists),
+  - Filament tenant cannot substitute for workspace context,
+  - legacy query aliases do not widen access or grant authority.
+
+### Phase 2 — Policy authority hardening
+
+- Remove forbidden fallbacks in `ProviderConnectionPolicy`:
+  - workspace authority must come from `WorkspaceContext` only,
+  - create tenant must come from explicit `environment_id` only.
+- Keep 404 vs 403 semantics consistent with repo rules.
+
+### Phase 3 — Resource scoping hardening
+
+- Ensure `ProviderConnectionResource` list/query scoping:
+  - requires workspace context for membership scope (no tenant-context fallback),
+  - uses `environment_id` only as an explicit filter, validated against workspace/access scope.
+- Ensure record pages/actions always use record-derived tenant/workspace (no hidden context authority).
+
+### Phase 4 — Validation and regression posture
+
+Run narrow tests first:
+
+- `cd apps/platform && ./vendor/bin/sail artisan test --compact tests/Feature/ProviderConnections --filter=ScopeHardening`
+- `cd apps/platform && ./vendor/bin/sail pint --dirty --format agent`
+
+Run optional browser smoke only if implementation changes visible CTA/copy:
+
+- `cd apps/platform && ./vendor/bin/sail artisan test --compact tests/Browser/Spec281ProviderConnectionScopeSmokeTest.php`
+
+## Deployment / Ops Impact
+
+- Migrations: none.
+- Env vars: none.
+- Queues/scheduler: none (no new job orchestration beyond existing provider operations).
+- Filament assets: unchanged.
+
+> **Fill when the feature touches shared provider/platform seams, identity scope, governed-subject taxonomy, compare strategy selection, provider connection descriptors, or operator vocabulary that may leak provider-specific semantics into platform-core truth. Docs-only or template-only work may use concise `N/A`.**
+
+- **Shared provider/platform boundary touched?**: [yes / no / N/A]
+- **Provider-owned seams**: [List or `N/A`]
+- **Platform-core seams**: [List or `N/A`]
+- **Neutral platform terms / contracts preserved**: [List or `N/A`]
+- **Retained provider-specific semantics and why**: [none / short explanation]
+- **Bounded extraction or follow-up path**: [none / document-in-feature / follow-up-spec / N/A]
+
+## Constitution Check
+
+*GATE: Must pass before Phase 0 research. Re-check after Phase 1 design.*
+
+- Inventory-first: clarify what is “last observed” vs snapshots/backups
+- Read/write separation: any writes require preview + confirmation + audit + tests
+- Graph contract path: Graph calls only via `GraphClientInterface` + `config/graph_contracts.php`
+- Deterministic capabilities: capability derivation is testable (snapshot/golden tests)
+- RBAC-UX: two planes (/admin vs /system) remain separated; cross-plane is 404; tenant-context routes (/admin/t/{tenant}/...) are tenant-scoped; canonical workspace-context routes under /admin remain tenant-safe; non-member tenant/workspace access is 404; member-but-missing-capability is 403; authorization checks use Gates/Policies + capability registries (no raw strings, no role-string checks)
+- Workspace isolation: non-member workspace access is 404; tenant-plane routes require an established workspace context; workspace context switching is separate from Filament Tenancy
+- RBAC-UX: destructive-like actions require `->requiresConfirmation()` and clear warning text
+- RBAC-UX: global search is tenant-scoped; non-members get no hints; inaccessible results are treated as not found (404 semantics)
+- Tenant isolation: all reads/writes tenant-scoped; cross-tenant views are explicit and access-checked
+- Run observability: long-running/remote/queued work creates/reuses `OperationRun`; start surfaces enqueue-only; Monitoring is DB-only; DB-only <2s actions may skip runs but security-relevant ones still audit-log; auth handshake exception OPS-EX-AUTH-001 allows synchronous outbound HTTP on `/auth/*` without `OperationRun`
+- OperationRun start UX: any feature that creates, queues, deduplicates, resumes, blocks, completes, or links `OperationRun` reuses the central OperationRun Start UX Contract; no local composition of queued toast/link/event/start-state messaging; `OperationRun UX Impact` is present in the active spec or plan
+- Ops-UX 3-surface feedback: if `OperationRun` is used, default feedback is toast intent-only + progress surfaces + exactly-once terminal `OperationRunCompleted` (initiator-only); queued DB notifications remain explicit opt-in through the shared start UX contract; running DB notifications stay disallowed
+- Ops-UX lifecycle: `OperationRun.status` / `OperationRun.outcome` transitions are service-owned (only via `OperationRunService`); context-only updates allowed outside
+- Ops-UX summary counts: `summary_counts` keys come from `OperationSummaryKeys::all()` and values are flat numeric-only
+- Ops-UX guards: CI has regression guards that fail with actionable output (file + snippet) when these patterns regress
+- Ops-UX system runs: initiator-null runs emit no terminal DB notification; audit remains via Monitoring; tenant-wide alerting goes through Alerts (not OperationRun notifications)
+- Automation: queued/scheduled ops use locks + idempotency; handle 429/503 with backoff+jitter
+- Data minimization: Inventory stores metadata + whitelisted meta; logs contain no secrets/tokens
+- Test governance (TEST-GOV-001): actual test-purpose classification, affected lanes, fixture/helper/factory/seed/context cost risks, heavy-family visibility, review-stop points, reviewer handoff, and any budget/baseline/trend follow-up are explicit; the narrowest proving lane mix is planned and any structural cost change has an escalation path
+- Proportionality (PROP-001): any new structure, layer, persisted truth, or semantic machinery is justified by current release truth, current operator workflow, and why a narrower solution is insufficient
+- No premature abstraction (ABSTR-001): no new factories, registries, resolvers, strategy systems, interfaces, type registries, or orchestration pipelines before at least 2 real concrete cases exist, unless security, tenant isolation, auditability, compliance evidence, or queue correctness require it now
+- Persisted truth (PERSIST-001): new tables/entities/artifacts represent independent product truth or lifecycle; convenience projections and UI helpers stay derived
+- Behavioral state (STATE-001): new states/statuses/reason codes change behavior, routing, permissions, lifecycle, audit, retention, or retry handling; presentation-only distinctions stay derived
+- UI semantics (UI-SEM-001): avoid turning badges, explanation text, trust/confidence labels, or detail summaries into mandatory interpretation frameworks; prefer direct domain-to-UI mapping
+- Shared pattern first (XCUT-001): cross-cutting interaction classes reuse existing shared contracts/presenters/builders/renderers first; any deviation is explicit, bounded, and justified against current-release truth
+- Provider boundary (PROV-001): shared provider/platform seams are classified as provider-owned vs platform-core; provider-specific semantics stay out of platform-core contracts, taxonomy, identifiers, compare semantics, and operator vocabulary unless explicitly justified; bounded extraction beats speculative multi-provider frameworks
+- V1 explicitness / few layers (V1-EXP-001, LAYER-001): prefer direct implementation, local mappings, and small helpers; any new layer replaces an old one or proves the old one cannot serve
+- Spec discipline / bloat check (SPEC-DISC-001, BLOAT-001): related semantic changes are grouped coherently, and any new enum, DTO/presenter, persisted entity, interface/registry/resolver, or taxonomy includes a proportionality review covering operator problem, insufficiency, narrowness, ownership cost, rejected alternative, and whether it is current-release truth
+- Badge semantics (BADGE-001): status-like badges use `BadgeCatalog` / `BadgeRenderer`; no ad-hoc mappings; new values include tests
+- Filament-native UI (UI-FIL-001): admin/operator surfaces use native Filament components or shared primitives first; no ad-hoc status UI, local semantic color/border decisions, or hand-built replacements when native/shared semantics exist; any exception is explicitly justified
+- Filament-native UI (UI-FIL-001): custom Filament UI follows `docs/ui/tenantpilot-enterprise-ui-standards.md`; no ad-hoc custom styling for cards, buttons, hovers, badges, icons, progress bars, empty states, or interactive rows
+- Filament-native UI (UI-FIL-001): if local Blade/Tailwind cards are
+  still necessary, they preserve dark mode correctness, spacing
+  consistency, badge semantics, action hierarchy, progressive
+  disclosure, accessibility, and Filament visual language
+- Filament-native UI (UI-FIL-001): custom Blade/Widget/Page surfaces
+  keep Filament-native interaction semantics, preserve one dominant
+  primary action per focused area, express state through
+  BADGE-001-aligned badges/labels/supporting text instead of arbitrary
+  button colors, and do not create independent button/card/spacing
+  systems
+- Filament-native UI (UI-FIL-001): hover, pointer, focus, shadow, or
+  similar interactive affordance appears only when a repo-real
+  route/action and permitted capability exist; non-interactive rows
+  stay visibly static
+- UI/UX surface taxonomy (UI-CONST-001 / UI-SURF-001): every changed operator-facing surface is classified as exactly one allowed surface type; ad-hoc interaction models are forbidden
+- Decision-first operating model (DECIDE-001): each changed
+  operator-facing surface is classified as Primary Decision,
+  Secondary Context, or Tertiary Evidence / Diagnostics; primary
+  surfaces justify the human-in-the-loop moment, default-visible info
+  is limited to first-decision needs, deep proof is progressive
+  disclosed, one governance case stays decidable in one context where
+  practical, navigation follows workflows not storage structures, and
+  automation / alerts reduce attention load instead of adding noise
+- Audience-aware disclosure (DECIDE-AUD-001 / OPSURF-001): detail or
+  status surfaces separate customer-readable decision content,
+  operator diagnostics, and support/raw evidence; customer-readable
+  default paths hide raw JSON, copied context, fingerprints, internal
+  reason ownership, platform reason families, and debug semantics;
+  one dominant next action is explicit; duplicate visible truth is
+  removed
+- UI/UX inspect model (UI-HARD-001): each list surface has exactly one primary inspect/open model; redundant View beside row click or identifier click is forbidden; edit-as-inspect is limited to Config-lite resources
+- UI/UX action hierarchy (UI-HARD-001 / UI-EX-001): standard CRUD and Registry rows expose at most one inline safe shortcut; destructive actions are grouped or in the detail header; queue exceptions are catalogued, justified, and tested
+- UI/UX scope, truth, and naming (UI-HARD-001 / UI-NAMING-001 / OPSURF-001): scope signals are truthful, canonical nouns stay stable across shells, critical operational truth is default-visible, and standard lists remain scanable
+- UI/UX placeholder ban (UI-HARD-001): empty `ActionGroup` / `BulkActionGroup` placeholders and declaration-only UI conformance are forbidden
+- UI naming (UI-NAMING-001): operator-facing labels use `Verb + Object`; scope (`Workspace`, `Tenant`) is never the primary action label; source/domain is secondary unless disambiguation is required; runs/toasts/audit prose use the same domain vocabulary; implementation-first terms do not appear in primary operator UI
+- Operator surfaces (OPSURF-001): `/admin` defaults are operator-first; default-visible content avoids raw implementation detail; diagnostics are explicitly revealed secondarily
+- Operator surfaces (OPSURF-001): execution outcome, data completeness, governance result, and lifecycle/readiness are modeled as distinct status dimensions when all apply; they are not collapsed into one ambiguous status
+- Operator surfaces (OPSURF-001): every mutating action communicates whether it changes TenantPilot only, the Microsoft tenant, or simulation only before execution
+- Operator surfaces (OPSURF-001): dangerous actions follow configuration → safety checks/simulation → preview → hard confirmation where required → execute, unless a spec documents an explicit exemption and replacement safeguards
+- Operator surfaces (OPSURF-001): workspace and tenant context remain explicit in navigation, actions, and page semantics; tenant surfaces do not silently expose workspace-wide actions
+- Operator surfaces (OPSURF-001): each new or materially refactored operator-facing page defines a page contract covering persona, surface type, operator question, default-visible info, diagnostics-only info, status dimensions, mutation scope, primary actions, and dangerous actions
+- Filament UI Action Surface Contract: for any new/modified Filament Resource/RelationManager/Page, define Header/Row/Bulk/Empty-State actions, ensure every List/Table has a surface-appropriate inspect affordance, remove redundant View when row click or identifier click already opens the same destination, keep standard CRUD/Registry rows to inspect plus at most one inline safe shortcut, group or relocate the rest to “More” or detail header, forbid empty bulk/overflow groups, require confirmations for destructive actions, write audit logs for mutations, enforce RBAC via central helpers (non-member 404, member missing capability 403), and ensure CI blocks merges if the contract is violated or not explicitly exempted
+- Filament UI UX-001 (Layout & IA): Create/Edit uses Main/Aside (3-col grid, Main=columnSpan(2), Aside=columnSpan(1)); all fields inside Sections/Cards (no naked inputs); View uses Infolists (not disabled edit forms); status badges use BADGE-001; empty states have specific title + explanation + 1 CTA; max 1 primary + 1 secondary header action (see HDR-001); tables provide search/sort/filters for core dimensions; shared layout builders preferred for consistency
+- Action-surface discipline (ACTSURF-001 / HDR-001): every changed
+  surface declares one broad action-surface class; the spec names the
+  one likely next operator action; navigation is separated from
+  mutation; record/detail/edit pages keep at most one visible primary
+  header action; monitoring/workbench surfaces separate scope/context,
+  selection actions, navigation, and object actions; risky or rare
+  actions are grouped and ordered by meaning/frequency/risk; any special
+  type or workflow-hub exception is explicit and justified
+- UI review workflow: native/custom classification, shared-family
+  relevance, state-layer ownership, repository-signal treatment,
+  exception path, and the active feature PR close-out entry stay
+  explicit without duplicating the same decision across spec, plan,
+  tasks, checklist, and close-out surfaces
+- UI/Productization coverage (UI-COV-001): every spec completes the UI
+  Surface Impact decision; changed reachable UI surfaces update
+  `docs/ui-ux-enterprise-audit/` coverage artifacts with page archetype,
+  design depth, repo-truth level, target pattern/mockup need,
+  customer-safe review need, and dangerous-action review need; a checked
+  `No UI surface impact` decision is used only with a short rationale
+
+## Test Governance Check
+
+> **Fill for any runtime-changing or test-affecting feature. Docs-only or template-only work may state concise `N/A` or `none`.**
+
+- **Test purpose / classification by changed surface**: [Unit / Feature / Heavy-Governance / Browser / N/A]
+- **Affected validation lanes**: [fast-feedback / confidence / heavy-governance / browser / profiling / junit / N/A]
+- **Why this lane mix is the narrowest sufficient proof**: [Why the chosen classification and lanes fit the actual proving purpose]
+- **Narrowest proving command(s)**: [Exact commands reviewers should run before merge]
+- **Fixture / helper / factory / seed / context cost risks**: [none / describe]
+- **Expensive defaults or shared helper growth introduced?**: [no / describe explicit opt-in path]
+- **Heavy-family additions, promotions, or visibility changes**: [none / describe]
+- **Surface-class relief / special coverage rule**: [standard-native relief / named special profile / N/A]
+- **Closing validation and reviewer handoff**: [What must be re-run, what reviewers should verify, and what exact proof command they should rely on]
+- **Budget / baseline / trend follow-up**: [none / describe]
+- **Review-stop questions**: [lane fit / breadth / hidden cost / heavy-family risk / escalation]
+- **Escalation path**: [none / document-in-feature / follow-up-spec / reject-or-split]
+- **Active feature PR close-out entry**: [Guardrail / Exception / Smoke Coverage / N/A]
+- **Why no dedicated follow-up spec is needed**: [Routine upkeep stays inside this feature unless recurring pain or structural lane changes justify a separate spec]
+
+## Project Structure
+
+### Documentation (this feature)
+
+```text
+specs/[###-feature]/
+├── plan.md              # This file (/speckit.plan command output)
+├── research.md          # Phase 0 output (/speckit.plan command)
+├── data-model.md        # Phase 1 output (/speckit.plan command)
+├── quickstart.md        # Phase 1 output (/speckit.plan command)
+├── contracts/           # Phase 1 output (/speckit.plan command)
+└── tasks.md             # Phase 2 output (/speckit.tasks command - NOT created by /speckit.plan)
+```
+
+### Source Code (repository root)
+<!--
+  ACTION REQUIRED: Replace the placeholder tree below with the concrete layout
+  for this feature. Delete unused options and expand the chosen structure with
+  real paths (e.g., apps/admin, packages/something). The delivered plan must
+  not include Option labels.
+-->
+
+```text
+# [REMOVE IF UNUSED] Option 1: Single project (DEFAULT)
+src/
+├── models/
+├── services/
+├── cli/
+└── lib/
+
+tests/
+├── contract/
+├── integration/
+└── unit/
+
+# [REMOVE IF UNUSED] Option 2: Web application (when "frontend" + "backend" detected)
+backend/
+├── src/
+│   ├── models/
+│   ├── services/
+│   └── api/
+└── tests/
+
+frontend/
+├── src/
+│   ├── components/
+│   ├── pages/
+│   └── services/
+└── tests/
+
+# [REMOVE IF UNUSED] Option 3: Mobile + API (when "iOS/Android" detected)
+api/
+└── [same as backend above]
+
+ios/ or android/
+└── [platform-specific structure: feature modules, UI flows, platform tests]
+```
+
+**Structure Decision**: [Document the selected structure and reference the real
+directories captured above]
+
+## Complexity Tracking
+
+> **Fill when Constitution Check has violations that must be justified OR when BLOAT-001 is triggered by new persistence, abstractions, states, or semantic frameworks.**
+
+| Violation | Why Needed | Simpler Alternative Rejected Because |
+|-----------|------------|-------------------------------------|
+| [e.g., 4th project] | [current need] | [why 3 projects insufficient] |
+| [e.g., Repository pattern] | [specific problem] | [why direct DB access insufficient] |
+
+## Proportionality Review
+
+> **Fill when the feature introduces a new enum/status family, DTO/presenter/envelope, persisted entity/table/artifact, interface/contract/registry/resolver, taxonomy/classification system, or cross-domain UI framework.**
+
+- **Current operator problem**: [What present-day workflow or risk requires this?]
+- **Existing structure is insufficient because**: [Why the current code cannot serve safely or clearly]
+- **Narrowest correct implementation**: [Why this shape is the smallest viable one]
+- **Ownership cost created**: [Maintenance, testing, cognitive load, migration, or review burden]
+- **Alternative intentionally rejected**: [Simpler option and why it failed]
+- **Release truth**: [Current-release truth or future-release preparation]
diff --git a/specs/339-provider-connection-scope-hardening/spec.md b/specs/339-provider-connection-scope-hardening/spec.md
new file mode 100644
index 00000000..f9981153
--- /dev/null
+++ b/specs/339-provider-connection-scope-hardening/spec.md
@@ -0,0 +1,235 @@
+# Feature Specification: Spec 339 - Provider Connection Scope Hardening
+
+**Feature Branch**: `339-provider-connection-scope-hardening`  
+**Created**: 2026-05-31  
+**Status**: Draft  
+**Input**: Candidate `provider-connection-scope-hardening` from `docs/product/spec-candidates.md` + user-provided draft + repo inspection of Provider Connection scope/authority seams.
+
+## Spec Candidate Check *(mandatory — SPEC-GATE-001)*
+
+- **Problem**: Provider Connections are credential-adjacent. Their scope and authorization authority must not come from hidden UI/session state (remembered environment) or Filament tenant fallbacks.
+- **Today's failure**:
+  - Provider Connection create authorization can still fall back to remembered environment (`WorkspaceContext::lastEnvironmentId`) or Filament tenant (`Filament::getTenant()`), allowing “implicit target environment” when `environment_id` is missing.
+  - Workspace authority can be inferred via Filament tenant when workspace context is missing, which is unsafe for a credential-adjacent surface.
+  - Legacy query keys (`tenant`, `tenant_id`, `managed_environment_id`) still exist in the ecosystem and must not regain authority via accidental parsing.
+- **User-visible improvement**: Operators can trust that Provider Connection list/view/create/edit/actions are scoped only by:
+  - explicit workspace context (required), plus
+  - explicit `environment_id` (filter/create), or
+  - record ownership (`ProviderConnection.workspace_id` + `ProviderConnection.managed_environment_id`) for view/edit/actions.
+- **Smallest enterprise-capable version**:
+  - define and enforce an explicit authority-source contract (allowed vs forbidden),
+  - remove hidden fallbacks in `ProviderConnectionPolicy` and Provider Connection resource query scoping,
+  - add targeted tests proving 404 vs 403 semantics and that legacy query aliases cannot grant authority.
+- **Explicit non-goals**:
+  - no provider-neutral target-scope refactor (Spec 281 family),
+  - no provider registry / OAuth redesign,
+  - no schema changes,
+  - no broad link/query cleanup beyond Provider Connections (defer to `canonical-link-query-cleanup` candidate).
+- **Permanent complexity imported**: a small set of contract tests + tightened policy/resource guardrails; no new persisted truth or abstraction layer.
+- **Why now**: Spec 338 tightened the workspace/environment scope contract. Provider Connections remain the main credential-adjacent hub; harden scope authority before adding more provider operations or onboarding variants.
+- **Why not local**: UI-only fixes do not guarantee consistent authority across create/view/actions. This must be enforced at the policy/resource boundary and guarded by tests.
+- **Approval class**: Core Enterprise (security / authorization hardening).
+- **Red flags triggered**: credential-adjacent surface + authorization semantics + cross-surface context drift. **Defense**: narrow scope, reuse existing `WorkspaceContext` + capabilities, and forbid new abstraction/persistence.
+- **Score**: Nutzen: 2 | Dringlichkeit: 2 | Scope: 1 | Komplexität: 1 | Produktnähe: 2 | Wiederverwendung: 2 | **Gesamt: 10/12**
+- **Decision**: approve.
+
+## Summary
+
+Provider Connections sit at the provider boundary and are credential-adjacent. This spec hardens their authority model so that:
+
+- **Create** requires an explicit `environment_id` (no remembered-environment or Filament-tenant fallback).
+- **View/Edit/Actions** derive scope from the `ProviderConnection` record (workspace + managed environment ownership).
+- **List filtering** uses explicit `environment_id` only, validated against the current workspace and access scope.
+- **Hidden context** (topbar remembered environment, Filament tenant context, legacy query aliases) must not grant authority.
+
+This is a narrow P1 security hardening slice following the Spec 338 contract work, with tests that make regressions obvious.
+
+## Spec Scope Fields *(mandatory)*
+
+- **Scope**: workspace (workspace-owned hub with optional environment filter)
+- **Primary Routes (representative)**:
+  - `/admin/provider-connections`
+  - `/admin/provider-connections?environment_id=<id>`
+  - `/admin/provider-connections/create?environment_id=<id>`
+  - `/admin/provider-connections/{record}` (view)
+  - `/admin/provider-connections/{record}/edit`
+- **Data Ownership**: `ProviderConnection` is workspace-owned and is linked to one `ManagedEnvironment` via `managed_environment_id`. No schema changes.
+- **RBAC**:
+  - Non-member / out-of-workspace access: 404 (deny-as-not-found)
+  - Member but missing capability: 403
+  - Capabilities used by this surface: `Capabilities::PROVIDER_VIEW`, `Capabilities::PROVIDER_MANAGE`, and existing dedicated-credential capability variants.
+
+## Authority / Scope Contract *(Spec 339)*
+
+### A. Allowed authority sources (canonical)
+
+Create:
+- explicit `environment_id` query parameter (validated and workspace-owned)
+- explicit environment selection in form state (only if a picker is introduced later)
+- workspace context from `WorkspaceContext` (required)
+
+View/Edit/Actions:
+- `ProviderConnection.workspace_id` + `ProviderConnection.managed_environment_id`
+- record → tenant (`ManagedEnvironment`) → `workspace_id` (derived)
+- workspace context from `WorkspaceContext` for deny-as-not-found semantics and list scoping
+
+### B. Forbidden authority sources (must never grant permission)
+
+- remembered environment (`WorkspaceContext::lastEnvironmentId` and related helpers)
+- Filament tenant fallback (`Filament::getTenant()`) as a source of workspace/environment authority
+- legacy query aliases (`tenant`, `tenant_id`, `managed_environment_id`) as authority inputs
+- Filament internal state/query keys as authority (`tableFilters[...]`, etc.)
+
+### C. 404 vs 403 semantics (authorization UX contract)
+
+- Non-member / no workspace context / wrong workspace / out-of-scope record: **404** (deny-as-not-found)
+- Member but missing capability: **403**
+
+## Required Runtime Decisions
+
+### D1 — Create requires explicit `environment_id` (no hidden fallback)
+
+Decision:
+- Provider Connection create is only valid with explicit `environment_id` that belongs to the current workspace.
+- Remembered environment and Filament tenant must never substitute for missing `environment_id`.
+
+Acceptance:
+- `/admin/provider-connections/create` without `environment_id` cannot be used to create a connection.
+- Wrong-workspace `environment_id` denies as 404.
+- Member without `PROVIDER_MANAGE` denies as 403.
+
+### D2 — Workspace authority requires explicit workspace context (no Filament fallback)
+
+Decision:
+- Workspace authority for Provider Connections must come from `WorkspaceContext` (session workspace), not from Filament tenant fallback.
+
+Acceptance:
+- If workspace context is missing, Provider Connections deny as 404 even if Filament tenant is set.
+
+### D3 — Environment filtering is explicit and inert
+
+Decision:
+- `environment_id` may filter list results but must be validated against current workspace and the user’s environment access scope.
+- Legacy query keys do not grant access and are not treated as authority.
+
+Acceptance:
+- `?managed_environment_id=...`, `?tenant=...`, `?tenant_id=...` do not grant access or widen results.
+
+## UI Surface Impact *(mandatory — UI-COV-001)*
+
+- [ ] No UI surface impact
+- [x] Existing page changed
+- [ ] New page/route added
+- [ ] Navigation changed
+- [ ] Filament panel/provider surface changed
+- [ ] New modal/drawer/wizard/action added
+- [ ] New table/form/state added
+- [ ] Customer-facing surface changed
+- [x] Dangerous action changed
+- [ ] Status/evidence/review presentation changed
+- [x] Workspace/environment context presentation changed
+
+## UI/Productization Coverage *(UI-COV-001)*
+
+- **Route/page/surface**: Provider Connections (list, view, create, edit) + credential-adjacent actions (dedicated credential management and provider operations) in `ProviderConnectionResource`.
+- **Current page archetype**: workspace admin “Integration/Settings” hub resource (credential-adjacent).
+- **Design depth**: Domain Pattern Surface (security/authority hardening; minimal UX change expected).
+- **Repo-truth level**: repo-verified (`ProviderConnectionResource`, `ProviderConnectionPolicy`, `WorkspaceContext`, `WorkspaceHubEnvironmentFilter` + existing ProviderConnections feature tests).
+- **Existing pattern reused**: Spec 338 scope contract + existing deny-as-not-found semantics, `WorkspaceContext`, capabilities, and existing ProviderConnections test families.
+- **New pattern required**: none (tighten existing seams; avoid new abstraction/persistence).
+- **Screenshot required**: no (unless implementation changes visible CTA/empty-state messaging; then add one targeted screenshot in the implementation PR).
+- **Page audit required**: no (existing archetype).
+- **Customer-safe review required**: no (operator-only surface).
+- **Dangerous-action review required**: yes (credential-adjacent actions must remain confirmation/authorization/audit-safe and scoped to record ownership).
+- **Coverage files to update (in implementation PR)**:
+  - [ ] `docs/ui-ux-enterprise-audit/route-inventory.md` (only if navigation entries/routes change; not expected)
+  - [ ] `docs/ui-ux-enterprise-audit/design-coverage-matrix.md` (no new surface; expected `no`)
+  - [x] `N/A - no new reachable UI surface added; authority hardening only`
+
+## Cross-Cutting / Shared Pattern Reuse *(mandatory)*
+
+- **Cross-cutting feature?**: yes
+- **Interaction class(es)**: navigation + scope presentation, authorization semantics, credential-adjacent action gating.
+- **Systems touched (expected)**:
+  - `apps/platform/app/Filament/Resources/ProviderConnectionResource.php`
+  - `apps/platform/app/Policies/ProviderConnectionPolicy.php`
+  - `apps/platform/app/Support/Workspaces/WorkspaceContext.php`
+  - `apps/platform/app/Support/Navigation/WorkspaceHubEnvironmentFilter.php`
+  - `apps/platform/tests/Feature/ProviderConnections/*`
+- **Existing pattern(s) to extend**: Spec 338 scope/authority contract (explicit `environment_id` filter, remembered environment is navigation-only, deny-as-not-found for out-of-scope).
+- **Allowed deviation and why**: none (tighten existing seams; no new surface frameworking).
+- **Consistency impact**: authority sources must match across list/create/policy/actions; tests must enforce that legacy query aliases and hidden context do not widen authority.
+- **Review focus**: “credential-adjacent authority comes from explicit input or record ownership only.”
+
+## OperationRun UX Impact
+
+- **Touches OperationRun start/completion/link UX?**: no
+- **N/A**: This spec hardens authority sources and authorization semantics. Provider operations that already run via `OperationRun` must remain scoped to the record’s owning environment/workspace; no new `OperationRun` types or start UX changes are introduced.
+
+## Provider Boundary / Platform Core Check
+
+- **Shared provider/platform boundary touched?**: yes
+- **Boundary classification**: platform-core authority (workspace/environment scope) + provider-owned identity (provider scope identifiers) must remain separated.
+- **Seams affected**: Provider Connection authority sources (workspace/environment), policy decisions, and filter/query semantics.
+- **Why this does not deepen provider coupling accidentally**: The contract uses neutral platform terms (`workspace`, `environment_id`, record ownership) and explicitly forbids conflating provider “tenant” identifiers with platform scope authority.
+- **Follow-up path**: none (follow-up work belongs in `canonical-link-query-cleanup` and/or Spec 281 family, not in this slice).
+
+## Testing / Lane / Runtime Impact *(mandatory for runtime behavior changes)*
+
+- **Test purpose / classification**: Feature (authorization/scope contract).
+- **Validation lane(s)**: fast-feedback (Feature). Browser smoke is optional and only justified if visible UX changes occur.
+- **Why this classification and these lanes are sufficient**: The risk is scope/authorization drift, which is best proven by targeted policy/resource tests (positive + negative cases) without introducing heavy or browser-wide cost by default.
+- **Planned validation commands**:
+  - `cd apps/platform && ./vendor/bin/sail artisan test --compact tests/Feature/ProviderConnections --filter=ScopeHardening`
+  - `cd apps/platform && ./vendor/bin/sail pint --dirty --format agent`
+
+## Acceptance Criteria
+
+- **AC1**: Provider Connection create requires explicit `environment_id`; remembered environment and Filament tenant cannot substitute.
+- **AC2**: Provider Connection list/view/edit/actions derive scope only from current workspace context + explicit `environment_id` (filter/create) or from record ownership (view/edit/actions).
+- **AC3**: Legacy query aliases (`tenant`, `tenant_id`, `managed_environment_id`) do not grant access or widen results.
+- **AC4**: 404 vs 403 semantics match the repo rules: out-of-scope/non-member is 404; missing capability is 403.
+- **AC5**: Targeted feature tests are green and make authority regressions obvious.
+
+## User Scenarios & Testing *(mandatory)*
+
+### User Story 1 — View Provider Connections safely (Priority: P1)
+
+As an operator in a workspace, I can list and view Provider Connections for environments I am entitled to, and I can optionally filter the list by an explicit environment.
+
+**Independent Test**: A user with workspace membership and `PROVIDER_VIEW` can list and view records in-scope; a non-member or wrong-workspace access is 404; a member without capability is 403; legacy query aliases do not widen access.
+
+**Acceptance Scenarios**:
+1. **Given** a workspace member with `PROVIDER_VIEW` on Environment A, **When** they visit `/admin/provider-connections`, **Then** the list contains only connections in environments they can access in the current workspace.
+2. **Given** the same user, **When** they visit `/admin/provider-connections?environment_id=<A>`, **Then** the list is filtered to Environment A and remains scope-safe.
+3. **Given** a user without workspace membership, **When** they hit Provider Connections routes, **Then** the response is deny-as-not-found (404).
+4. **Given** a member without `PROVIDER_VIEW`, **When** they attempt to list/view, **Then** the response is 403.
+5. **Given** any user, **When** they add `tenant`, `tenant_id`, or `managed_environment_id` query keys, **Then** those keys do not grant access or change authority behavior.
+
+### User Story 2 — Create Provider Connection only with explicit target environment (Priority: P1)
+
+As an operator, I can create a Provider Connection only when I explicitly choose the target environment (by passing `environment_id`) and I am authorized for that environment.
+
+**Independent Test**: Create is impossible without explicit `environment_id`, even if a remembered environment or Filament tenant exists.
+
+**Acceptance Scenarios**:
+1. **Given** a member with `PROVIDER_MANAGE` on Environment A, **When** they open `/admin/provider-connections/create?environment_id=<A>`, **Then** create is allowed and the record is owned by Environment A + the current workspace.
+2. **Given** a request to `/admin/provider-connections/create` without `environment_id`, **When** the user has a remembered environment, **Then** create is still denied (no implicit fallback).
+3. **Given** an `environment_id` from another workspace, **When** the user attempts create, **Then** the response is 404.
+4. **Given** a member without `PROVIDER_MANAGE`, **When** they attempt create for an in-scope environment, **Then** the response is 403.
+
+### User Story 3 — Perform credential-adjacent actions with record-derived authority (Priority: P2)
+
+As an operator, credential-adjacent actions (dedicated credential management, provider operations) execute only when I am authorized for the record’s owning environment/workspace, independent of remembered environment or Filament tenant state.
+
+**Independent Test**: A record-bound action uses the record’s ownership and denies 404/403 correctly.
+
+**Acceptance Scenarios**:
+1. **Given** a Provider Connection record owned by Environment A, **When** a user with access to Environment A triggers an action, **Then** the action is authorized using record ownership and capability checks.
+2. **Given** the same record, **When** a user’s remembered environment is Environment B, **Then** authorization still uses record ownership (A), not hidden context.
+3. **Given** a member without the dedicated credential capability, **When** they attempt dedicated credential actions, **Then** the response is 403.
+
+## Follow-up spec candidates
+
+- `canonical-link-query-cleanup` (broader link/query inventory + alias cleanup after scope contract)
+- `environment-resource-context-follow-through` (reduce hidden Filament context reliance inside selected environment resources)
diff --git a/specs/339-provider-connection-scope-hardening/tasks.md b/specs/339-provider-connection-scope-hardening/tasks.md
new file mode 100644
index 00000000..f39b4265
--- /dev/null
+++ b/specs/339-provider-connection-scope-hardening/tasks.md
@@ -0,0 +1,114 @@
+# Tasks: Spec 339 - Provider Connection Scope Hardening
+
+- Input: `specs/339-provider-connection-scope-hardening/spec.md`, `specs/339-provider-connection-scope-hardening/plan.md`
+- Preparation status: implementation-ready.
+
+**Tests**: Required. This spec hardens credential-adjacent scope/authorization semantics.
+
+## Test Governance Checklist
+
+- [x] Lane assignment is explicit and narrowest sufficient (Feature).
+- [x] No new default-heavy helpers/factories/seeds are introduced.
+- [x] Scope/authority changes are guarded by deterministic tests before refactors.
+- [x] Any exception resolves as `document-in-feature`, `follow-up-spec`, or `reject-or-split`.
+
+## Phase 1: Preparation And Repo Truth (blocks runtime changes)
+
+**Purpose**: Confirm repo truth and identify the exact forbidden fallback seams before changing behavior.
+
+- [x] T001 Re-read `spec.md` + `plan.md` + this `tasks.md`.
+- [x] T002 Confirm working tree intent and record baseline commit (`git status`, `git log -1`).
+- [x] T003 Inspect the confirmed authority seams:
+  - `apps/platform/app/Policies/ProviderConnectionPolicy.php`:
+    - `currentWorkspace()` (forbidden fallback via `Filament::getTenant()`).
+    - `resolveCreateTenant()` (forbidden fallbacks via remembered environment + Filament tenant).
+    - record-derived checks for workspace/environment ownership (ensure these remain the canonical authority for view/edit/actions).
+  - `apps/platform/app/Filament/Resources/ProviderConnectionResource.php`:
+    - `applyMembershipScope()` (must not infer workspace via tenant context).
+    - `resolveRequestedEnvironment()` / `WorkspaceHubEnvironmentFilter` use (explicit `environment_id` only).
+  - `apps/platform/app/Support/Workspaces/WorkspaceContext.php`:
+    - `lastEnvironmentId()` and remembered-environment helpers (navigation-only; must not grant create authority).
+- [x] T004 Inventory existing ProviderConnections tests and identify the best location for new regression tests:
+  - `apps/platform/tests/Feature/ProviderConnections/ProviderConnectionListAuthorizationTest.php`
+  - `apps/platform/tests/Feature/ProviderConnections/ProviderConnectionsWorkspaceHubContractTest.php`
+  - `apps/platform/tests/Feature/ProviderConnections/AuthorizationSemanticsTest.php`
+  - `apps/platform/tests/Feature/ProviderConnections/RequiredFiltersTest.php`
+
+## Phase 2: Add failing contract tests first
+
+**Purpose**: Make authority changes reviewable and regression-proof.
+
+- [x] T005 Add a new Spec 339 test proving create requires explicit `environment_id`:
+  - Create is denied when `/admin/provider-connections/create` is requested without `environment_id`,
+  - even if a remembered environment exists in session (`WorkspaceContext::lastEnvironmentId`).
+  - Implemented via: `apps/platform/tests/Feature/ProviderConnections/ScopeHardeningAuthoritySourcesTest.php`
+- [x] T006 Add a test proving workspace authority does not fall back to Filament tenant:
+  - When workspace context is missing, Provider Connection access is deny-as-not-found (404),
+  - even if `Filament::getTenant()` is set.
+  - Implemented via:
+    - `apps/platform/tests/Feature/ProviderConnections/ScopeHardeningPolicyWorkspaceAuthorityTest.php`
+    - `apps/platform/tests/Feature/ProviderConnections/ScopeHardeningResourceWorkspaceAuthorityTest.php`
+- [x] T007 Add a test proving legacy query aliases do not grant authority:
+  - `?managed_environment_id=...`, `?tenant=...`, `?tenant_id=...` must not widen list scope or unlock create.
+  - Implemented via: `apps/platform/tests/Feature/ProviderConnections/ScopeHardeningAuthoritySourcesTest.php`
+- [x] T008 Add a test proving wrong-workspace environment IDs deny as 404:
+  - `environment_id` from another workspace must not authorize create or list filtering.
+
+## Phase 3: Policy authority hardening (Spec 339 contract)
+
+**Purpose**: Remove forbidden authority fallbacks and enforce the 404/403 semantics contract.
+
+- [x] T009 Update `apps/platform/app/Policies/ProviderConnectionPolicy.php::currentWorkspace()`:
+  - remove `Filament::getTenant()` as an authority source for workspace selection,
+  - keep workspace membership validation,
+  - keep deny-as-not-found (404) behavior when workspace context is missing.
+- [x] T010 Update `apps/platform/app/Policies/ProviderConnectionPolicy.php::resolveCreateTenant()`:
+  - require explicit `environment_id`,
+  - remove remembered-environment fallback and Filament-tenant fallback,
+  - ensure wrong-workspace `environment_id` denies as 404.
+- [x] T011 Confirm 404 vs 403 semantics for all policy methods:
+  - non-member / out-of-scope record → 404,
+  - member missing capability → 403.
+
+## Phase 4: Resource scoping hardening (no hidden context authority)
+
+**Purpose**: Ensure list/query and record surfaces do not infer authority from hidden context.
+
+- [x] T012 Update `apps/platform/app/Filament/Resources/ProviderConnectionResource.php::applyMembershipScope()`:
+  - remove fallback that infers workspace ID from tenant context when session workspace is missing,
+  - keep query empty (no results) when workspace context is missing.
+- [x] T013 Confirm Provider Connections list filtering uses explicit `environment_id` only:
+  - validate `environment_id` against current workspace and access scope,
+  - ignore legacy query aliases as authority.
+- [x] T014 Confirm record pages and action dispatchers use record-derived tenant/workspace authority, not remembered environment or Filament tenant.
+
+## Phase 5: Credential-adjacent actions audit
+
+**Purpose**: Ensure high-risk actions remain safe and record-scoped.
+
+- [x] T015 Audit all actions on `ProviderConnectionResource` (edit + dedicated credential actions + provider operations):
+  - confirm policy methods are used consistently,
+  - confirm destructive-like actions retain `->requiresConfirmation()`,
+  - confirm record ownership controls scope for all actions.
+- [x] T016 Confirm audit posture remains intact for credential-adjacent mutations:
+  - no new audit event families are introduced in this slice,
+  - existing audit logging remains correct and record-scoped.
+
+## Phase 6: Optional UX clarification (only if needed)
+
+- [x] T017 If create is denied without `environment_id`, ensure the list empty state or guidance makes the required next step obvious (filter/select an environment first) without introducing a new picker or redesign. (No changes needed.)
+
+## Phase 7: Validation
+
+- [x] T018 Run narrow tests first:
+  - `cd apps/platform && ./vendor/bin/sail artisan test --compact tests/Feature/ProviderConnections --filter=ScopeHardening`
+- [x] T019 Run formatting and patch checks:
+  - `cd apps/platform && ./vendor/bin/sail pint --dirty --format agent`
+  - `git diff --check`
+
+## Explicit Non-Goals
+
+- [x] NT001 Do not add migrations, new tables, or new persisted truth.
+- [x] NT002 Do not redesign Provider Connections UX or navigation placement.
+- [x] NT003 Do not introduce a new scope/authority abstraction framework.
+- [x] NT004 Do not reopen provider-neutral target-scope/identity refactors (Spec 281 family).