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]>

.sqlx/query-2390b39f2359c75dc13c5749adbb912534d29ed74a920e3940338cb63369693f.json

@@ -0,0 +1,32 @@
+{
+  "db_name": "PostgreSQL",
+  "query": "SELECT a.run_id, a.id AS approval_id, a.status\n           FROM approvals a\n           JOIN agent_runs r ON r.id = a.run_id\n           WHERE a.status IN ('approved', 'rejected')\n             AND r.state = 'awaiting_approval'\n           ORDER BY a.decided_at",
+  "describe": {
+    "columns": [
+      {
+        "ordinal": 0,
+        "name": "run_id",
+        "type_info": "Uuid"
+      },
+      {
+        "ordinal": 1,
+        "name": "approval_id",
+        "type_info": "Uuid"
+      },
+      {
+        "ordinal": 2,
+        "name": "status",
+        "type_info": "Text"
+      }
+    ],
+    "parameters": {
+      "Left": []
+    },
+    "nullable": [
+      false,
+      false,
+      false
+    ]
+  },
+  "hash": "2390b39f2359c75dc13c5749adbb912534d29ed74a920e3940338cb63369693f"
+}