# Implementation Plan: Drift MVP (044)

**Branch**: `feat/044-drift-mvp` | **Date**: 2026-01-12 | **Spec**: `specs/044-drift-mvp/spec.md`
**Input**: Feature specification from `specs/044-drift-mvp/spec.md`

## Summary

Introduce a generic, persisted Finding pipeline and implement Drift as the first generator.

- Drift compares Inventory Sync Runs for the same selection scope (`scope_key`).
- Baseline run = previous successful run for the same scope; comparison run = latest successful run.
- Findings are persisted with deterministic fingerprints and support MVP triage (`new` → `acknowledged`).
- UI is DB-only for label/name resolution (no render-time Graph calls).
- Drift generation is tracked via `BulkOperationRun` for status/errors across refresh and idempotency.

## Technical Context

**Language/Version**: PHP 8.4.x
**Framework**: Laravel 12
**Admin UI**: Filament v4 + Livewire v3
**Storage**: PostgreSQL (JSONB)
**Testing**: Pest v4
**Target Platform**: Docker (Sail-first local), Dokploy container deployments
**Project Type**: Laravel monolith
**Performance Goals**:
- Drift generation happens async (job), with deterministic output
- Drift listing remains filterable and index-backed
**Constraints**:
- Tenant isolation for all reads/writes
- No render-time Graph calls; labels resolved from DB caches
- Evidence minimization (sanitized allowlist; no raw payload dumps)
- Drift generation is job-only and uses `BulkOperationRun` (`resource=drift`, `action=generate`) as the canonical run record
**Scale/Scope**:
- Tenants may have large inventories; findings must be indexed for typical filtering

## Constitution Check

*GATE: Must pass before Phase 0 research. Re-check after Phase 1 design.*

- Inventory-first: Drift is derived from Inventory Sync Runs and Inventory Items (“last observed” state).
- Read/write separation: Drift generation is analytical; writes are limited to triage acknowledgement and must be audited + tested.
- Graph contract path: Drift UI performs no Graph calls; Graph calls remain isolated in existing Inventory/Graph client layers.
- Deterministic capabilities: drift scope derives from existing selection hashing and inventory type registries.
- Tenant isolation: all reads/writes tenant-scoped; no cross-tenant leakage.
- Automation: drift generation is queued; jobs are deduped/locked per scope+run pair and observable.
- Data minimization: store only minimized evidence JSON; logs contain no secrets/tokens.

## Project Structure

### Documentation (this feature)

```text
specs/044-drift-mvp/
├── plan.md              # This file (/speckit.plan output)
├── research.md          # Phase 0 output
├── data-model.md        # Phase 1 output
├── quickstart.md        # Phase 1 output
├── contracts/           # Phase 1 output
│   └── admin-findings.openapi.yaml
└── tasks.md             # Phase 2 output (/speckit.tasks)
```

### Source Code (repository root)

```text
app/
├── Filament/
│   ├── Pages/
│   │   └── DriftLanding.php                 # drift landing page (summary + generation status)
│   └── Resources/
│       └── FindingResource/                 # list/detail + acknowledge action (tenant-scoped)
├── Jobs/
│   └── GenerateDriftFindingsJob.php         # async generator (on-demand)
├── Models/
│   └── Finding.php                          # generic finding model
└── Services/
    └── Drift/
        ├── DriftFindingGenerator.php        # computes deterministic findings for baseline/current
        ├── DriftHasher.php                  # baseline_hash/current_hash helpers
        └── DriftScopeKey.php                # scope_key is InventorySyncRun.selection_hash (single canonical definition)

database/migrations/
└── 2026_.._.._create_findings_table.php

tests/Feature/Drift/
├── DriftGenerationDeterminismTest.php
├── DriftTenantIsolationTest.php
└── DriftAcknowledgeTest.php
```

**Structure Decision**: Laravel monolith using Filament pages/resources and queued jobs.

## Complexity Tracking

> **Fill ONLY if Constitution Check has violations that must be justified**

| Violation | Why Needed | Simpler Alternative Rejected Because |
|-----------|------------|-------------------------------------|
| (none) | | |

## Phase 0 Output (Research)

Completed in `specs/044-drift-mvp/research.md`.

## Phase 1 Output (Design)

Completed in:

- `specs/044-drift-mvp/data-model.md`
- `specs/044-drift-mvp/contracts/`
- `specs/044-drift-mvp/quickstart.md`

## Phase 2 Planning Notes

Next step is expanding `specs/044-drift-mvp/tasks.md` (via `/speckit.tasks`) with phased, test-first implementation tasks.
