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.

internal/core/app/execution.go

@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"log/slog"
+	"strings"
 	"time"
 
 	"github.com/dtoro/oikos/internal/core/domain"
@@ -19,10 +20,10 @@ import (
 // (MCP `run`/`docker_exec` tools, and any future REST surface) converge
 // here — one policy, one audit trail (plan §4.A).
 type ExecutionService struct {
-	policy    *PolicyService
-	exec      ports.CommandExecutor
-	resolver  ports.TargetResolver
-	recorder  ports.ExecutionRecorder
+	policy   *PolicyService
+	exec     ports.CommandExecutor
+	resolver ports.TargetResolver
+	recorder ports.ExecutionRecorder
 }
 
 // NewExecutionService wires the service.
@@ -199,6 +200,31 @@ func (s *ExecutionService) finalize(ctx context.Context, execID domain.UUID, sta
 	}
 }
 
+// DispatchQueued runs a previously-recorded queued execution (status
+// 'proposed' or 'approved') over the CommandExecutor port. The command is
+// derived from the execution's action column the same way the legacy worker
+// did: "action_name:{json_params}" extracts params["command"], else the
+// action string is the raw command. Used by the execworker poller adapter.
+func (s *ExecutionService) DispatchQueued(ctx context.Context, execID domain.UUID, targetSlug, action string) (string, error) {
+	return s.dispatch(ctx, execID, targetSlug, queuedCommand(action), nil, nil)
+}
+
+// queuedCommand extracts the actual shell command from an execution's action
+// column. Format: "action_name:{json_params}" → params["command"]; otherwise
+// the action string is itself the raw command.
+func queuedCommand(action string) string {
+	if idx := strings.Index(action, ":"); idx > 0 && idx < len(action)-1 {
+		rawParams := action[idx+1:]
+		var params map[string]any
+		if json.Unmarshal([]byte(rawParams), &params) == nil {
+			if c, ok := params["command"].(string); ok && c != "" {
+				return c
+			}
+		}
+	}
+	return action
+}
+
 func jsonOutBytes(out string) []byte {
 	b, _ := json.Marshal(map[string]any{"output": out})
 	return b