fix(cliproxy): make version cache backend-specific for proper switching

- Add backend parameter to version cache functions (read/write/path)
- Store cache at bin/{backend}/.version-cache.json instead of shared location
- Pass backend through checkForUpdates() and BinaryManager
- Add refetchType: 'all' to force immediate query refetch on backend change
- Add cliproxy-server-config query invalidation for consistency

src/cliproxy/binary-manager.ts

@@ -85,7 +85,12 @@ export class BinaryManager {
 
   /** Check for updates by comparing installed version with latest release */
   async checkForUpdates(): Promise<UpdateCheckResult> {
-    return checkForUpdates(this.config.binPath, this.config.version, this.config.verbose);
+    return checkForUpdates(
+      this.config.binPath,
+      this.config.version,
+      this.config.verbose,
+      this.backend
+    );
   }
 
   /** Get full path to binary executable */

src/cliproxy/binary/version-cache.ts

@@ -16,10 +16,10 @@ import { DEFAULT_BACKEND } from '../platform-detector';
 import type { CLIProxyBackend } from '../types';
 
 /**
- * Get path to version cache file
+ * Get path to version cache file (backend-specific)
  */
-export function getVersionCachePath(): string {
+export function getVersionCachePath(backend: CLIProxyBackend = DEFAULT_BACKEND): string {
-  return path.join(getCliproxyDir(), '.version-cache.json');
+  return path.join(getBinDir(), backend, '.version-cache.json');
 }
 
 /**
@@ -30,10 +30,10 @@ export function getVersionPinPath(backend: CLIProxyBackend = DEFAULT_BACKEND): s
 }
 
 /**
- * Read version cache if still valid
+ * Read version cache if still valid (backend-specific)
  */
-export function readVersionCache(): VersionCache | null {
+export function readVersionCache(backend: CLIProxyBackend = DEFAULT_BACKEND): VersionCache | null {
-  const cachePath = getVersionCachePath();
+  const cachePath = getVersionCachePath(backend);
   if (!fs.existsSync(cachePath)) {
     return null;
   }
@@ -55,10 +55,13 @@ export function readVersionCache(): VersionCache | null {
 }
 
 /**
- * Write version to cache
+ * Write version to cache (backend-specific)
  */
-export function writeVersionCache(version: string): void {
+export function writeVersionCache(
-  const cachePath = getVersionCachePath();
+  version: string,
+  backend: CLIProxyBackend = DEFAULT_BACKEND
+): void {
+  const cachePath = getVersionCachePath(backend);
   const cache: VersionCache = {
     latestVersion: version,
     checkedAt: Date.now(),

src/cliproxy/binary/version-checker.ts

@@ -17,7 +17,12 @@ import {
   GITHUB_API_ALL_RELEASES,
   VersionListResult,
 } from './types';
-import { CLIPROXY_MAX_STABLE_VERSION, CLIPROXY_FAULTY_RANGE } from '../platform-detector';
+import {
+  CLIPROXY_MAX_STABLE_VERSION,
+  CLIPROXY_FAULTY_RANGE,
+  DEFAULT_BACKEND,
+} from '../platform-detector';
+import type { CLIProxyBackend } from '../types';
 
 /**
  * Compare semver versions (true if latest > current)
@@ -72,16 +77,18 @@ export async function fetchLatestVersion(verbose = false): Promise<string> {
 /**
  * Check for updates by comparing installed version with latest release
  * Uses cache to avoid hitting GitHub API on every run
+ * Cache is backend-specific to handle different repos for original vs plus
  */
 export async function checkForUpdates(
   binPath: string,
   configVersion: string,
-  verbose = false
+  verbose = false,
+  backend: CLIProxyBackend = DEFAULT_BACKEND
 ): Promise<UpdateCheckResult> {
   const currentVersion = readInstalledVersion(binPath, configVersion);
 
-  // Try cache first
+  // Try cache first (backend-specific)
-  const cache = readVersionCache();
+  const cache = readVersionCache(backend);
   if (cache) {
     if (verbose) {
       console.error(`[cliproxy] Using cached version: ${cache.latestVersion}`);
@@ -98,7 +105,7 @@ export async function checkForUpdates(
   // Fetch from GitHub API
   const latestVersion = await fetchLatestVersion(verbose);
   const now = Date.now();
-  writeVersionCache(latestVersion);
+  writeVersionCache(latestVersion, backend);
 
   return {
     hasUpdate: isNewerVersion(latestVersion, currentVersion),

ui/src/hooks/use-cliproxy.ts

@@ -353,8 +353,10 @@ export function useUpdateBackend() {
       api.cliproxyServer.updateBackend(backend, force),
     onSuccess: () => {
       // Invalidate all queries that depend on backend setting
-      queryClient.invalidateQueries({ queryKey: ['cliproxy-update-check'] });
+      // Use refetchType: 'all' to force immediate refetch even if query is stale
-      queryClient.invalidateQueries({ queryKey: ['cliproxy-versions'] });
+      queryClient.invalidateQueries({ queryKey: ['cliproxy-update-check'], refetchType: 'all' });
+      queryClient.invalidateQueries({ queryKey: ['cliproxy-versions'], refetchType: 'all' });
+      queryClient.invalidateQueries({ queryKey: ['cliproxy-server-config'], refetchType: 'all' });
       queryClient.invalidateQueries({ queryKey: ['proxy-status'] });
       queryClient.invalidateQueries({ queryKey: ['cliproxy-stats'] });
       toast.success('Backend updated');