feat(api): add frontend API and Query hooks for proxy config

Add TypeScript wrappers and TanStack Query hooks for:
- Global proxy config (address, port, logging)
- Per-app proxy config (failover, timeouts, circuit breaker)
- Proxy takeover status management

src/lib/query/index.ts

@@ -1,3 +1,4 @@
 export * from "./queryClient";
 export * from "./queries";
 export * from "./mutations";
+export * from "./proxy";