[Bug][Desktop 2.2.1] Console UI loads before backend is ready at startup — model list and plugin panels stay blank until manual refresh

Environment

• QwenPaw Desktop 2.2.1, Windows 11 (WebView2 console)
• Plugins installed: chrome, computer-use, longtext-input, prompt-optimizer-plus, qwenpaw-plugin-file-tools, qwenpaw-plugin-process-tools

Bug description

On desktop app startup the Console frequently renders incompletely:

• the model list fails to load,
• plugin panels (Long-text Input, Prompt Optimizer Plus) render empty,
• some page sections stay partially loaded.

A manual refresh (F5) immediately fixes everything. This reproduces on most cold starts.

Root cause (log evidence from one affected boot)

The desktop window opens and the SPA fires its first-wave fetches while the backend is still initializing:

00:15:31  backend process spawned
00:15:39  Server ready in 6.606s (agents loading in background)   <- HTTP starts listening only here
00:15:39  plugin directory scan #1 (6 plugins discovered)
00:15:44  Workspace started successfully / Agent startup complete <- ~13s after spawn

First-wave requests hit a backend that is either not listening yet (connection refused) or has not registered all routes yet (404). The SPA does not retry failed initial fetches, so affected panels stay blank. A refresh works because the backend is fully up by then.

The same race is visible mid-session: the SPA polls GET /api/tool-calls/{session}/{call_id} and receives a burst of 404s before the tool-call record becomes available, then gets 200.

Suggested fix

• Desktop: only load the Console SPA after the backend reports ready (or keep a loading state until then)
• Console SPA: retry failed initial fetches with backoff, or re-fetch when the backend / WS connection (re)establishes

Workaround

Wait ~15s after launch, or refresh manually.