feat: add workspace baseline compare matrix (#221)
## Summary
- add a workspace-scoped baseline compare matrix page under baseline profiles
- derive matrix tenant summaries, subject rows, cell states, freshness, and trust from existing snapshots, compare runs, and findings
- add confirmation-gated `Compare assigned tenants` actions on the baseline detail and matrix surfaces without introducing a workspace umbrella run
- preserve matrix navigation context into tenant compare and finding drilldowns and add centralized matrix badge semantics
- include spec, plan, data model, contracts, quickstart, tasks, and focused feature/browser coverage for Spec 190
## Verification
- `cd apps/platform && ./vendor/bin/sail artisan test --compact tests/Unit/Badges/BaselineCompareMatrixBadgesTest.php tests/Feature/Baselines/BaselineCompareMatrixBuilderTest.php tests/Feature/Baselines/BaselineCompareMatrixCompareAllActionTest.php tests/Feature/Baselines/BaselineComparePerformanceGuardTest.php tests/Feature/Filament/BaselineCompareMatrixPageTest.php tests/Feature/Filament/BaselineProfileCompareStartSurfaceTest.php tests/Feature/Rbac/BaselineCompareMatrixAuthorizationTest.php tests/Feature/Guards/ActionSurfaceContractTest.php tests/Feature/Guards/NoAdHocStatusBadgesTest.php tests/Feature/Guards/NoDiagnosticWarningBadgesTest.php`
- `cd apps/platform && ./vendor/bin/sail bin pint --dirty --format agent`
- completed an integrated-browser smoke flow locally for matrix render, differ filter, finding drilldown round-trip, and `Compare assigned tenants` confirmation/action
Co-authored-by: Ahmed Darrazi <ahmed.darrazi@live.de>
Reviewed-on: #221
ahmido
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