P2 BLOCKING exit green: approval interception chain end-to-end

- tc-tools: Effect declarations -> §15 GatedCategory mapping, deny-by-default
  external reach, taint invariant property-tested (tainted external effects
  are NEVER auto-allowed)
- tc-safety: pending approvals with exact payload+preview, CAS decide with
  audit + single-use grant in one tx, checkpoint suspend/load, exclusive
  resume claim, expiry sweep, decided-unresumed work queue (migration 0004
  adds the outbox the gated email.send tool writes)
- tc-runtime: resumable LoopState checkpointed to agent_runs; gated tool ->
  approval row -> approval_required/run_suspended events -> suspend; resume
  consumes the grant BEFORE executing (spent grant = no execution), rejection
  feeds a structured refusal in-band; durable resume sweeper; continuous
  journal seq across suspension (tested). ContentPart::Text became a struct
  variant — internally-tagged newtype primitives don't serialize
- tc-api: GET/decide approvals endpoints (409 double-decide, tenant
  isolation), decision triggers in-process resume; full chain proven over
  HTTP incl. gateway resumeFrom continuation
- frontend: approval_required/run_suspended events, suspended reply state,
  inline ApprovalCard (§10: summary, category, exact payload preview,
  approve/reject -> decide + stream re-attach), /approvals queue page, nav
- E2E (14 journeys, workers:1 to serialize the shared backend): gated email
  blocks with disabled composer -> approve -> continuation + ✓ step + reload
  replay; reject -> ✗ step, nothing executed; queue page decides pending

106 Rust + 61 frontend tests + 14 Playwright journeys green.

Co-Authored-By: Claude Fable 5 <[email protected]>

frontend/src/app/(workspace)/approvals/page.tsx

@@ -0,0 +1,20 @@
+import { ApprovalQueue } from "@/components/safety/ApprovalQueue";
+import { fetchPendingApprovals } from "@/lib/api/approvals";
+
+// The approvals queue (§10): every gated action waiting on a human.
+export default async function ApprovalsPage() {
+  const approvals = await fetchPendingApprovals();
+  return (
+    <section className="mx-auto max-w-3xl px-8 py-12">
+      <h1 className="text-2xl font-semibold tracking-tight">Approvals</h1>
+      <p className="pt-1 text-sm text-muted-foreground">
+        {approvals.length === 0
+          ? "All clear — no actions awaiting review."
+          : `${approvals.length} ${
+              approvals.length === 1 ? "action awaits" : "actions await"
+            } your review. Nothing runs until you decide.`}
+      </p>
+      <ApprovalQueue approvals={approvals} />
+    </section>
+  );
+}