fix: recover chat state after idle reconnects

Resyncs active sessions after hidden upstream stream reconnects
Recovers orphaned streaming parts with active-session snapshots
Adds coverage for event-stream reconnect behavior

packages/ui/package.json

@@ -46,7 +46,7 @@
     "@fontsource/ibm-plex-sans": "^5.1.1",
     "@ibm/plex": "^6.4.1",
     "@lezer/highlight": "^1.2.3",
-    "@opencode-ai/sdk": "^1.17.9",
+    "@opencode-ai/sdk": "^1.17.12",
     "@pierre/diffs": "1.3.0-beta.6",
     "@replit/codemirror-vim": "^6.3.0",
     "@simplewebauthn/browser": "13.3.0",