feat: Phase 9 gaps closed — ApprovalService.Decide convergence, execlog fold, execworker poller

- ApprovalService (core/app/approval.go) + ApprovalRepo (postgres adapter) with
  full decide transaction: HMAC token verify, approval flip, execution un-gate,
  session-scoped window keys (+session suffix matching GovernanceStore gate),
  nomos session flip, audit+event on failure abort. httpapi DecideApproval now
  a thin presenter delegating to the service. ListPending payload format fixed
  (json.Unmarshal not raw-wrap).
- execlog folded into postgres adapter: internal/execlog deleted, NewExecutionLog
  / ReadExecutionLog live in the db package, callers updated (mcp, httpapi).
- execworker poller over ExecutionService.DispatchQueued: advisory lock leak
  fixed (defer/recover per execution), correlation_id preserved via Finalize
  event emission (ExecRunRepo.Finalize now emits execution.{status} with
  correlation_id from the row).
- Phase 8 session export-rename completed: Store, New, and all 53 methods
  exported; cmd/nomos/ agent.go fixed to use session.PendingContinuation etc.
- Coverage gates: ExecutionService.Submit 93.1%, PolicyService.Decide 100%.
- Plans index updated, VERSION bumped to 0.36.0.

plans/index.md

@@ -6,7 +6,9 @@ went sideways, open an investigation.
 
 ## Active
 
-All plans reviewed and moved to `done/` — see the [Done table](#done) below.
+| Date | Title |
+| ---- | ----- |
+| 2026-08-16 | [dsh-as-agent: replace nomos with DeepSeek Harness](2026-08-16-dsh-as-agent-replace-nomos.md) |
 
 ## Done