refactor: fix architectural issues across frontend and backend

Address all architecture review findings:

P0 fixes:
- Add API key authentication for admin endpoints (analytics, replay, openapi)
  and WebSocket connections via ADMIN_API_KEY env var
- Add PostgreSQL-backed PgSessionManager and PgInterruptManager for
  multi-worker production deployments (in-memory defaults preserved)

P1 fixes:
- Implement actual tool generation in OpenAPI approve_job endpoint
  using generate_tool_code() and generate_agent_yaml()
- Add missing clarification, interrupt_expired, and tool_result message
  handlers in frontend ChatPage

P2 fixes:
- Replace monkey-patching on CompiledStateGraph with typed GraphContext
- Replace 9-param dispatch_message with WebSocketContext dataclass
- Extract duplicate _envelope() into shared app/api_utils.py
- Replace mutable module-level counter with crypto.randomUUID()
- Remove hardcoded mock data from ReviewPage, use api.ts wrappers
- Remove `as any` type escape from ReplayPage

All 516 tests passing, 0 TypeScript errors.

backend/app/replay/api.py

@@ -3,16 +3,23 @@
 from __future__ import annotations
 
 import re
-from typing import TYPE_CHECKING, Annotated, Any
+from typing import TYPE_CHECKING, Annotated
 
-from fastapi import APIRouter, HTTPException, Query, Request
+from fastapi import APIRouter, Depends, HTTPException, Query, Request
+
+from app.api_utils import envelope
+from app.auth import require_admin_api_key
 
 _THREAD_ID_PATTERN = re.compile(r"^[a-zA-Z0-9\-_]{1,128}$")
 
 if TYPE_CHECKING:
     from psycopg_pool import AsyncConnectionPool
 
-router = APIRouter(prefix="/api", tags=["replay"])
+router = APIRouter(
+    prefix="/api",
+    tags=["replay"],
+    dependencies=[Depends(require_admin_api_key)],
+)
 
 _COUNT_CONVERSATIONS_SQL = """
 SELECT COUNT(*) FROM conversations
@@ -38,10 +45,6 @@ async def get_pool(request: Request) -> AsyncConnectionPool:
     return request.app.state.pool
 
 
-def _envelope(data: Any, *, success: bool = True, error: str | None = None) -> dict:
-    return {"success": success, "data": data, "error": error}
-
-
 @router.get("/conversations")
 async def list_conversations(
     request: Request,
@@ -62,7 +65,7 @@ async def list_conversations(
         )
         rows = await cursor.fetchall()
 
-    return _envelope({
+    return envelope({
         "conversations": [dict(row) for row in rows],
         "total": total,
         "page": page,
@@ -119,4 +122,4 @@ async def get_replay(
             for s in page_steps
         ],
     }
-    return _envelope(data)
+    return envelope(data)