fix: keep new sessions grouped by project

Preserves session directory metadata across live updates
Keeps desktop and mobile session lists in project groups
Adds regression coverage for session grouping

package.json

@@ -90,7 +90,7 @@
     "@ibm/plex": "^6.4.1",
     "@lezer/highlight": "^1.2.3",
     "@octokit/rest": "^22.0.1",
-    "@opencode-ai/sdk": "^1.15.10",
+    "@opencode-ai/sdk": "^1.15.13",
     "@radix-ui/react-collapsible": "^1.1.12",
     "@radix-ui/react-dialog": "^1.1.15",
     "@radix-ui/react-dropdown-menu": "^2.1.16",