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/nomos/assent/assent_test.go

@@ -11,8 +11,8 @@ func TestIsAssent_Positive(t *testing.T) {
 		"ok go ahead and run it",
 	}
 	for _, c := range cases {
-		if !isAssent(c) {
-			t.Errorf("isAssent(%q) = false, want true", c)
+		if !IsAssent(c) {
+			t.Errorf("IsAssent(%q) = false, want true", c)
 		}
 	}
 }
@@ -24,8 +24,8 @@ func TestIsAssent_Negative(t *testing.T) {
 		"maybe later", "",
 	}
 	for _, c := range cases {
-		if isAssent(c) {
-			t.Errorf("isAssent(%q) = true, want false", c)
+		if IsAssent(c) {
+			t.Errorf("IsAssent(%q) = true, want false", c)
 		}
 	}
 }
@@ -38,8 +38,8 @@ func TestIsAssent_NegationBeatsAssentWord(t *testing.T) {
 		"wait, not yet please",
 	}
 	for _, c := range cases {
-		if isAssent(c) {
-			t.Errorf("isAssent(%q) = true, want false (negation should block)", c)
+		if IsAssent(c) {
+			t.Errorf("IsAssent(%q) = true, want false (negation should block)", c)
 		}
 	}
 }
@@ -47,7 +47,7 @@ func TestIsAssent_NegationBeatsAssentWord(t *testing.T) {
 // TestIsAssent_WholeWordBoundary regression-tests a real false positive found
 // live: the old substring check matched "yes" inside "yesterday" (and would
 // equally match "confirm" inside "confirmed"/"unconfirmed" for
-// isTypedConfirmation below) because only negation used a word-boundary
+// IsTypedConfirmation below) because only negation used a word-boundary
 // check — assent/confirm words used a bare strings.Contains. Confirmed via a
 // throwaway probe before being fixed; kept here permanently so a future
 // change can't silently reintroduce it.
@@ -57,14 +57,14 @@ func TestIsAssent_WholeWordBoundary(t *testing.T) {
 		"my eyesight isn't great, what does that say",
 	}
 	for _, c := range cases {
-		if isAssent(c) {
-			t.Errorf("isAssent(%q) = true, want false (word-boundary: 'yes' must not match inside 'yesterday'/'eyesight')", c)
+		if IsAssent(c) {
+			t.Errorf("IsAssent(%q) = true, want false (word-boundary: 'yes' must not match inside 'yesterday'/'eyesight')", c)
 		}
 	}
 }
 
 // TestIsTypedConfirmation_ContractedNegation regression-tests the other real
-// false positive: isTypedConfirmation gates DESTRUCTIVE actions, and
+// false positive: IsTypedConfirmation gates DESTRUCTIVE actions, and
 // "confirm" matching inside "confirmed" combined with contracted negatives
 // ("haven't") not being in negationWords meant a message that explicitly
 // says the operator has NOT confirmed something could read as confirming it.
@@ -75,8 +75,8 @@ func TestIsTypedConfirmation_ContractedNegation(t *testing.T) {
 		"we can't confirm that until tomorrow",
 	}
 	for _, c := range cases {
-		if isTypedConfirmation(c) {
-			t.Errorf("isTypedConfirmation(%q) = true, want false (contracted negation should block)", c)
+		if IsTypedConfirmation(c) {
+			t.Errorf("IsTypedConfirmation(%q) = true, want false (contracted negation should block)", c)
 		}
 	}
 }
@@ -89,8 +89,8 @@ func TestIsTypedConfirmation(t *testing.T) {
 		"yes I confirm",
 	}
 	for _, c := range positive {
-		if !isTypedConfirmation(c) {
-			t.Errorf("isTypedConfirmation(%q) = false, want true", c)
+		if !IsTypedConfirmation(c) {
+			t.Errorf("IsTypedConfirmation(%q) = false, want true", c)
 		}
 	}
 	negative := []string{
@@ -98,8 +98,8 @@ func TestIsTypedConfirmation(t *testing.T) {
 		"no, don't confirm yet", "wait", "",
 	}
 	for _, c := range negative {
-		if isTypedConfirmation(c) {
-			t.Errorf("isTypedConfirmation(%q) = true, want false (only explicit confirm should pass)", c)
+		if IsTypedConfirmation(c) {
+			t.Errorf("IsTypedConfirmation(%q) = true, want false (only explicit confirm should pass)", c)
 		}
 	}
 }