Add app update detection and multi-folder project support

Feature 1 - Update Detection: Query Gitea releases API on startup (3s
delay) and every 24h, compare patch versions by platform, show pulsing
"Update" button in TopBar with dialog for release notes/downloads.
Settings: auto-check toggle, manual check, dismiss per-version.

Feature 2 - Multi-Folder Projects: Replace single `path` with
`paths: Vec<ProjectPath>` (host_path + mount_name). Each folder mounts
to `/workspace/{mount_name}`. Auto-migrate old single-path JSON on load.
Container recreation via paths-fingerprint label. AddProjectDialog and
ProjectCard support add/remove/edit of multiple folders.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/src/components/layout/TopBar.tsx

@@ -1,22 +1,62 @@
+import { useState } from "react";
 import { useShallow } from "zustand/react/shallow";
 import TerminalTabs from "../terminal/TerminalTabs";
 import { useAppState } from "../../store/appState";
+import { useSettings } from "../../hooks/useSettings";
+import UpdateDialog from "../settings/UpdateDialog";
 
 export default function TopBar() {
-  const { dockerAvailable, imageExists } = useAppState(
-    useShallow(s => ({ dockerAvailable: s.dockerAvailable, imageExists: s.imageExists }))
+  const { dockerAvailable, imageExists, updateInfo, appVersion, setUpdateInfo } = useAppState(
+    useShallow(s => ({
+      dockerAvailable: s.dockerAvailable,
+      imageExists: s.imageExists,
+      updateInfo: s.updateInfo,
+      appVersion: s.appVersion,
+      setUpdateInfo: s.setUpdateInfo,
+    }))
   );
+  const { appSettings, saveSettings } = useSettings();
+  const [showUpdateDialog, setShowUpdateDialog] = useState(false);
+
+  const handleDismiss = async () => {
+    if (appSettings && updateInfo) {
+      await saveSettings({
+        ...appSettings,
+        dismissed_update_version: updateInfo.version,
+      });
+    }
+    setUpdateInfo(null);
+    setShowUpdateDialog(false);
+  };
 
   return (
-    <div className="flex items-center h-10 bg-[var(--bg-secondary)] border border-[var(--border-color)] rounded-lg overflow-hidden">
-      <div className="flex-1 overflow-x-auto pl-2">
-        <TerminalTabs />
+    <>
+      <div className="flex items-center h-10 bg-[var(--bg-secondary)] border border-[var(--border-color)] rounded-lg overflow-hidden">
+        <div className="flex-1 overflow-x-auto pl-2">
+          <TerminalTabs />
+        </div>
+        <div className="flex items-center gap-2 px-4 flex-shrink-0 text-xs text-[var(--text-secondary)]">
+          {updateInfo && (
+            <button
+              onClick={() => setShowUpdateDialog(true)}
+              className="px-2 py-0.5 rounded text-xs font-medium bg-[var(--accent)] text-white animate-pulse hover:bg-[var(--accent-hover)] transition-colors"
+            >
+              Update
+            </button>
+          )}
+          <StatusDot ok={dockerAvailable === true} label="Docker" />
+          <StatusDot ok={imageExists === true} label="Image" />
+        </div>
       </div>
-      <div className="flex items-center gap-2 px-4 flex-shrink-0 text-xs text-[var(--text-secondary)]">
-        <StatusDot ok={dockerAvailable === true} label="Docker" />
-        <StatusDot ok={imageExists === true} label="Image" />
-      </div>
-    </div>
+      {showUpdateDialog && updateInfo && (
+        <UpdateDialog
+          updateInfo={updateInfo}
+          currentVersion={appVersion}
+          onDismiss={handleDismiss}
+          onClose={() => setShowUpdateDialog(false)}
+        />
+      )}
+    </>
   );
 }