feat: Ollama Cloud quota tracker + proactive background OAuth refresh

Ollama: replace informational stub with real quota tracker hitting ollama.com/api/usage (session 5h + weekly 7d, 0..1 ratio) and /api/me plan label; bind handler to apiKey + add features.usageApikey so apikey connections work.

Token refresh: add backgroundTokenRefresh scheduler that refreshes OAuth connections within max(provider lead, 30min) of expiry, independent of inbound traffic (10s after boot, then every 5min, unref'd timers, DISABLE_BACKGROUND_TOKEN_REFRESH kill-switch, fail-open per tick/connection). Registered from custom-server.js (listening) and initializeApp.js. checkAndRefreshToken gains opt-in {force} for the scheduler; request path unchanged.

src/shared/services/initializeApp.js

@@ -112,6 +112,12 @@ async function runHeavyStartup() {
       .then(({ startQuotaAutoPing }) => startQuotaAutoPing())
       .catch((e) => console.log("[AutoPing] scheduler start failed:", e.message));
   }
+
+  // Proactive OAuth token refresh (e.g. grok-cli ~6h TTL). Module is idempotent
+  // and also started from custom-server.js when that entry is used.
+  import("@/sse/services/backgroundTokenRefresh.js")
+    .then(({ startBackgroundTokenRefresh }) => startBackgroundTokenRefresh())
+    .catch((e) => console.log("[BackgroundTokenRefresh] scheduler start failed:", e.message));
 }
 
 function hasQuotaAutoPingEnabled(settings) {