# Release Investigation Routes Reconnection

## Module
Web

## Status
IMPLEMENTED

## Sprint
SPRINT_20260308_022_FE_unreachable_release_investigation_routes

## Description
Integrated disconnected release-investigation route families (timeline, deploy-diff, change-trace) into the canonical Releases product under a bounded `/releases/investigation/` prefix. The investigation timeline is mounted as a secondary route to avoid colliding with the shipped run workspace tab at `/releases/runs/:runId/timeline`.

## Canonical URL Contract
- `/releases/investigation/timeline` - Investigation timeline overview
- `/releases/investigation/timeline/:correlationId` - Correlated event drill-in
- `/releases/investigation/deploy-diff` - Deployment diff workspace; direct load shows a recovery state when no `from`/`to` digests are present
- `/releases/investigation/change-trace` - Change trace workspace; direct load shows a recovery state until a comparison or trace id is selected
- `/releases/investigation/change-trace/:traceId` - Specific trace detail

## Direct-Load Workspace Contract
- `/releases/investigation/deploy-diff` no longer fails with `Missing Parameters`. Direct navigation now shows `No Comparison Selected` plus recovery actions back to `/releases/deployments` and `/releases/overview`.
- `/releases/investigation/change-trace` no longer renders an inert `No Change Trace Loaded` shell. Direct navigation now shows `No Comparison Selected` plus recovery actions to `/releases/deployments`, or back to deploy-diff when `from`/`to` digests are already present.
- Both workspaces preserve tenant/scope query context when it exists and fall back to the canonical `demo-prod` tenant on a fresh shell load.

## Timeline Decision
**Bounded-secondary-route** (not absorb-into-run-workspace). The investigation timeline is a correlation-based tool that spans multiple services by correlationId, which is conceptually different from the run workspace's timeline tab showing run execution flow. Mounting it under `/releases/investigation/timeline` avoids URL collision and keeps both capabilities distinct.

## Implementation Details
- **Route file**: `src/Web/StellaOps.Web/src/app/routes/releases.routes.ts`
  - Added three `loadChildren` entries under `investigation/` prefix
- **Feature routes updated**:
  - `src/Web/StellaOps.Web/src/app/features/timeline/timeline.routes.ts` - Added breadcrumb, title, sprint ref
  - `src/Web/StellaOps.Web/src/app/features/deploy-diff/deploy-diff.routes.ts` - Updated canonical URL reference
  - `src/Web/StellaOps.Web/src/app/features/change-trace/change-trace.routes.ts` - Added breadcrumb, title, sprint ref
- **Tests**: `src/Web/StellaOps.Web/src/app/routes/releases.routes.spec.ts`
- **Recheck (2026-03-09)**:
  - `deploy-diff` is now backed by the live lineage compare contract instead of the dead `/api/v1/sbom/diff` path.
  - `change-trace` is now backed by the restored `/api/change-traces/build` and `/api/change-traces/{traceId}` compatibility endpoints in SbomService.
  - Focused verification passed on `src/Web/StellaOps.Web/src/app/features/deploy-diff/pages/deploy-diff.page.spec.ts` and `src/Web/StellaOps.Web/src/app/features/change-trace/change-trace-viewer.component.spec.ts`.

## Deliberately Excluded Legacy Behaviors
- The old timeline route at `/timeline` (standalone top-level) is not revived
- Direct mounting at `/releases/runs/:runId/timeline` for the investigation timeline is explicitly avoided (that path is owned by the run workspace)