Phase 28-36 body of work

Accumulated since a6f12e2 (Phase 21 Rust port + Phase 27 versioning):

- Phase 36: embed_semaphore on VectorState (permits=1) serializes
  seed embed calls — prevents sidecar socket collisions under
  concurrent /seed stress load
- Phase 31+: run_stress.ts 6-task diverse stress scaffolding;
  run_e2e_rated.ts + orchestrator.ts tightening
- Catalog dedupe cleanup: 16 duplicate manifests removed; canonical
  candidates.parquet (10.5MB -> 76KB) + placements.parquet (1.2MB ->
  11KB) regenerated post-dedupe; fresh manifests for active datasets
- vectord: harness EvalSet refinements (+181), agent portfolio
  rotation + ingest triggers (+158), autotune + rag adjustments
- catalogd/storaged/ingestd/mcp-server: misc tightening
- docs: Phase 28-36 PRD entries + DECISIONS ADR additions;
  control-plane pivot banner added to top of docs/PRD.md (pointing
  at docs/CONTROL_PLANE_PRD.md which lands in next commit)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

crates/vectord/Cargo.toml

@@ -9,6 +9,7 @@ storaged = { path = "../storaged" }
 aibridge = { path = "../aibridge" }
 catalogd = { path = "../catalogd" }
 queryd = { path = "../queryd" }
+futures = { workspace = true }
 # ADR-019 firewall — vectord-lance owns its own Arrow 57 / Lance 4 deps.
 # Public API uses only std types so no version conflict propagates here.
 vectord-lance = { path = "../vectord-lance" }
@@ -24,3 +25,4 @@ arrow = { workspace = true }
 chrono = { workspace = true }
 instant-distance = { workspace = true }
 uuid = { workspace = true }
+sha2 = { workspace = true }