feat: Add Go module and workspace test fixtures

- Created expected JSON files for Go modules and workspaces.
- Added go.mod and go.sum files for example projects.
- Implemented private module structure with expected JSON output.
- Introduced vendored dependencies with corresponding expected JSON.
- Developed PostgresGraphJobStore for managing graph jobs.
- Established SQL migration scripts for graph jobs schema.
- Implemented GraphJobRepository for CRUD operations on graph jobs.
- Created IGraphJobRepository interface for repository abstraction.
- Added unit tests for GraphJobRepository to ensure functionality.

docs/db/reports/scheduler-graphjobs-postgres-plan.md

@@ -0,0 +1,57 @@
+# Scheduler Graph Jobs: PostgreSQL Migration Plan (2025-12-06)
+
+## Goals
+- Replace Mongo-based GraphJobStore/PolicyRunService with PostgreSQL equivalents.
+- Keep graph job determinism (status transitions, ordering) and tenant isolation.
+- Provide schema, repository surface, and migration steps to unblock PG-T7.1.2a (Cleanup Wave A).
+
+## Proposed Schema (schema: `scheduler`)
+- `graph_jobs`
+  - `id UUID PK`
+  - `tenant_id TEXT NOT NULL`
+  - `type SMALLINT NOT NULL` (0=build,1=overlay)
+  - `status SMALLINT NOT NULL` (queued, running, completed, failed, canceled)
+  - `payload JSONB NOT NULL` (serialized GraphBuildJob/GraphOverlayJob)
+  - `created_at TIMESTAMPTZ NOT NULL DEFAULT now()`
+  - `updated_at TIMESTAMPTZ NOT NULL DEFAULT now()`
+  - `correlation_id TEXT NULL`
+  - Indexes: `idx_graph_jobs_tenant_status` (tenant_id, status, created_at DESC), `idx_graph_jobs_tenant_type_status` (tenant_id, type, status, created_at DESC)
+
+- `graph_job_events`
+  - `id BIGSERIAL PK`
+  - `job_id UUID NOT NULL REFERENCES graph_jobs(id) ON DELETE CASCADE`
+  - `tenant_id TEXT NOT NULL`
+  - `status SMALLINT NOT NULL`
+  - `payload JSONB NOT NULL`
+  - `created_at TIMESTAMPTZ NOT NULL DEFAULT now()`
+  - Index: `idx_graph_job_events_job` (job_id, created_at DESC)
+
+## Repository Contracts
+- `IGraphJobRepository` (Postgres)
+  - `ValueTask InsertAsync(GraphBuildJob job, CancellationToken ct)`
+  - `ValueTask InsertAsync(GraphOverlayJob job, CancellationToken ct)`
+  - `ValueTask<bool> TryReplaceAsync(GraphBuildJob job, GraphJobStatus expected, CancellationToken ct)`
+  - `ValueTask<bool> TryReplaceOverlayAsync(GraphOverlayJob job, GraphJobStatus expected, CancellationToken ct)`
+  - `ValueTask<GraphBuildJob?> GetBuildJobAsync(string tenantId, string id, CancellationToken ct)`
+  - `ValueTask<GraphOverlayJob?> GetOverlayJobAsync(string tenantId, string id, CancellationToken ct)`
+  - `ValueTask<IReadOnlyCollection<GraphBuildJob>> ListBuildJobsAsync(string tenantId, GraphJobStatus? status, int limit, CancellationToken ct)`
+  - `ValueTask<IReadOnlyCollection<GraphOverlayJob>> ListOverlayJobsAsync(string tenantId, GraphJobStatus? status, int limit, CancellationToken ct)`
+  - `ValueTask AppendEventAsync(GraphJobEvent evt, CancellationToken ct)`
+
+## Migration
+- New migration file: `014_graph_jobs.sql` under `src/Scheduler/__Libraries/StellaOps.Scheduler.Storage.Postgres/Migrations` with the tables above.
+
+## DI Changes
+- Replace `AddSchedulerMongoStorage` and `MongoGraphJobStore` in WebService with `AddSchedulerPostgresStorage` and new `PostgresGraphJobStore` implementing `IGraphJobStore`.
+- Worker.Backfill: swap Mongo options to Postgres options; use Postgres repos from `StellaOps.Scheduler.Storage.Postgres`.
+
+## Tests
+- Add Postgres integration tests for `PostgresGraphJobRepository` covering insert/list/update/expected-status checks and event log.
+- Update WebService/Worker tests to use Postgres fixtures; remove Mongo fixtures.
+
+## Rollback
+- If regressions occur, revert migration + DI switch; Mongo storage remains in history.
+
+## Owners
+- Schema/repo: Scheduler Guild
+- DI/tests: Scheduler Guild