Add integration tests for migration categories and execution

- Implemented MigrationCategoryTests to validate migration categorization for startup, release, seed, and data migrations.
- Added tests for edge cases, including null, empty, and whitespace migration names.
- Created StartupMigrationHostTests to verify the behavior of the migration host with real PostgreSQL instances using Testcontainers.
- Included tests for migration execution, schema creation, and handling of pending release migrations.
- Added SQL migration files for testing: creating a test table, adding a column, a release migration, and seeding data.

docs/implplan/SPRINT_0512_0001_0001_bench.md

@@ -16,6 +16,8 @@
 - docs/modules/signals/architecture.md (for reachability benches)
 - docs/modules/policy/architecture.md
 
+> **BLOCKED Tasks:** Before working on BLOCKED tasks, review [BLOCKED_DEPENDENCY_TREE.md](./BLOCKED_DEPENDENCY_TREE.md) for root blockers and dependencies.
+
 ## Delivery Tracker
 | # | Task ID | Status | Key dependency / next step | Owners | Task Definition |
 | --- | --- | --- | --- | --- | --- |
@@ -27,9 +29,9 @@
 | P6 | PREP-BENCH-SIG-26-002-BLOCKED-ON-26-001-OUTPU | DONE (2025-11-20) | Prep doc at `docs/benchmarks/signals/bench-sig-26-002-prep.md`; depends on 26-001 datasets. | Bench Guild · Policy Guild | Blocked on 26-001 outputs. <br><br> Document artefact/deliverable for BENCH-SIG-26-002 and publish location so downstream tasks can proceed. |
 | 1 | BENCH-GRAPH-21-001 | DONE (2025-12-02) | PREP-BENCH-GRAPH-21-001-NEED-GRAPH-BENCH-HARN | Bench Guild · Graph Platform Guild | Build graph viewport/path benchmark harness (50k/100k nodes) measuring Graph API/Indexer latency, memory, and tile cache hit rates. |
 | 2 | BENCH-GRAPH-21-002 | DONE (2025-12-02) | PREP-BENCH-GRAPH-21-002-BLOCKED-ON-21-001-HAR | Bench Guild · UI Guild | Add headless UI load benchmark (Playwright) for graph canvas interactions to track render times and FPS budgets. |
-| 3 | BENCH-GRAPH-24-002 | BLOCKED | Waiting for 50k/100k graph fixture (SAMPLES-GRAPH-24-003) | Bench Guild · UI Guild | Implement UI interaction benchmarks (filter/zoom/table operations) citing p95 latency; integrate with perf dashboards. |
-| 4 | BENCH-IMPACT-16-001 | BLOCKED | PREP-BENCH-IMPACT-16-001-IMPACT-INDEX-DATASET | Bench Guild · Scheduler Team | ImpactIndex throughput bench (resolve 10k productKeys) + RAM profile. |
-| 5 | BENCH-POLICY-20-002 | BLOCKED | PREP-BENCH-POLICY-20-002-POLICY-DELTA-SAMPLE | Bench Guild · Policy Guild · Scheduler Guild | Add incremental run benchmark measuring delta evaluation vs full; capture SLA compliance. |
+| 3 | BENCH-GRAPH-24-002 | BLOCKED | Waiting for 50k/100k graph fixture (SAMPLES-GRAPH-24-003) | Bench Guild · UI Guild | Implement UI interaction benchmarks (filter/zoom/table operations) citing p95 latency; integrate with perf dashboards. |
+| 4 | BENCH-IMPACT-16-001 | BLOCKED | PREP-BENCH-IMPACT-16-001-IMPACT-INDEX-DATASET | Bench Guild · Scheduler Team | ImpactIndex throughput bench (resolve 10k productKeys) + RAM profile. |
+| 5 | BENCH-POLICY-20-002 | BLOCKED | PREP-BENCH-POLICY-20-002-POLICY-DELTA-SAMPLE | Bench Guild · Policy Guild · Scheduler Guild | Add incremental run benchmark measuring delta evaluation vs full; capture SLA compliance. |
 | 6 | BENCH-SIG-26-001 | BLOCKED | PREP-BENCH-SIG-26-001-REACHABILITY-SCHEMA-FIX | Bench Guild · Signals Guild | Develop benchmark for reachability scoring pipeline (facts/sec, latency, memory) using synthetic callgraphs/runtime batches. |
 | 7 | BENCH-SIG-26-002 | BLOCKED | PREP-BENCH-SIG-26-002-BLOCKED-ON-26-001-OUTPU | Bench Guild · Policy Guild | Measure policy evaluation overhead with reachability cache hot/cold; ensure ≤8 ms p95 added latency. |
 | 8 | BENCH-DETERMINISM-401-057 | DONE (2025-11-27) | Feed-freeze hash + SBOM/VEX bundle list from Sprint 0401. | Bench Guild · Signals Guild · Policy Guild (`bench/determinism`, `docs/benchmarks/signals/bench-determinism.md`) | Run cross-scanner determinism bench from 23-Nov advisory; publish determinism% and CVSS delta σ; CI workflow `bench-determinism` runs harness and uploads manifests/results; offline runner added. |