fix: address prerelease workflow review bugs

- Type checkVersion() with VersionInfo interface; fixes TS errors in
  checkAndNotifyVersion() where object type blocked property access
- Don't cache fallback on !resp.ok or fetch throw; prevents a transient
  GitHub outage from poisoning the 5-min version cache
- Guard parseInt result with Number.isFinite() in compareVersions;
  malformed -pre.abc tags no longer silently compare as equal via NaN
- Pre-compute stripped versions before sort in checkVersion(); avoids
  mutating input array and redundant replace() calls in comparator
- Bump GitHub releases fetch from per_page=20 to per_page=100
- Store appVersion in authStore; populate from App.tsx getAppConfig call
  and remove redundant getAppConfig fetch in Navbar useEffect
- Type GitHubPanel error/expanded state as string|null and Record<number,boolean>

client/src/App.tsx

@@ -88,7 +88,7 @@ function RootRedirect() {
 }
 
 export default function App() {
-  const { loadUser, isAuthenticated, demoMode, setDemoMode, setDevMode, setIsPrerelease, setHasMapsKey, setServerTimezone, setAppRequireMfa, setTripRemindersEnabled } = useAuthStore()
+  const { loadUser, isAuthenticated, demoMode, setDemoMode, setDevMode, setIsPrerelease, setAppVersion, setHasMapsKey, setServerTimezone, setAppRequireMfa, setTripRemindersEnabled } = useAuthStore()
   const { loadSettings } = useSettingsStore()
 
   useEffect(() => {
@@ -99,6 +99,7 @@ export default function App() {
       if (config?.demo_mode) setDemoMode(true)
       if (config?.dev_mode) setDevMode(true)
       if (config?.is_prerelease !== undefined) setIsPrerelease(config.is_prerelease)
+      if (config?.version) setAppVersion(config.version)
       if (config?.has_maps_key !== undefined) setHasMapsKey(config.has_maps_key)
       if (config?.timezone) setServerTimezone(config.timezone)
       if (config?.require_mfa !== undefined) setAppRequireMfa(!!config.require_mfa)