Convex-only Slice 1: clients talk to Convex, Flue is a private worker

Normalize the topology so web/desktop/mobile clients communicate only with
Convex. Convex admits durable commands, dispatches private Flue turns through
FLUE_URL, and stores the product-facing result before clients observe it.

- Normalized relational schema: organizations, projects, conversations/turns/
  messages/attachments, signals/sources/constraints, works/events/attachments.
- Conversation turns queued in Convex; the agent runAction dispatches to Flue
  and persists assistant response, signals, and proposed work back into Convex.
- Browser chat moved off the Flue transport: use-chat-agent now reads reactive
  Convex rows and sends through conversationMessages.send.
- Fixed signed-in blank screen: gate all product queries on useConvexAuth
  (isAuthenticated && !isRefreshing) plus personal-org bootstrap.
- Pinned react/react-dom to 19.2.8 via catalog to fix SSR dual-React crash.
- Removed ~16.6k net lines: daemon, AgentOS/Orb, project issues/runs/artifacts,
  todos, browser Flue transport, mobile execution views, smoke scripts.

Verified end-to-end on cheaptricks: connect repo, send actionable message,
Flue turn completes, Signal + proposed Work created with exact provenance,
persists across refresh.

packages/ui/package.json

@@ -25,8 +25,8 @@
     "clsx": "^2.1.1",
     "lucide-react": "catalog:",
     "next-themes": "catalog:",
-    "react": "^19.2.7",
-    "react-dom": "^19.2.7",
+    "react": "catalog:",
+    "react-dom": "catalog:",
     "shadcn": "^4.12.0",
     "shiki": "^4.3.1",
     "sonner": "catalog:",