fix: harden home clash-mode card against /configs read failures

Recover from controller read/switch failures on the mode card instead of
showing a bare "communication error":

- fall back to the tolerant get_clash_mode command (then runtime config)
  when the live /configs mode is unavailable,
- optimistically reflect the clicked mode and write it through to the
  getClashConfig cache so a failed refetch can't flash back the old value,
- surface patch failures via showNotice on both the home card and the
  proxies page (patchClashMode can now reject), and
- revalidate getClashMode/getRuntimeConfig on refresh-clash-config so a
  once-empty fallback can recover.

src/hooks/use-clash.ts

@@ -4,6 +4,7 @@ import { getVersion } from 'tauri-plugin-mihomo-api'
 
 import {
   getClashInfo,
+  getClashMode,
   getRuntimeConfig,
   patchClashConfig,
 } from '@/services/cmds'
@@ -65,6 +66,16 @@ export const useRuntimeConfig = (shouldFetch: boolean = true) => {
   })
 }
 
+// Fault-tolerant fallback for the current proxy mode, read straight from the
+// saved clash config on the backend (bypasses the strict BaseConfig path).
+export const useClashMode = (shouldFetch: boolean = true) => {
+  return useQuery({
+    queryKey: ['getClashMode'],
+    queryFn: getClashMode,
+    enabled: shouldFetch,
+  })
+}
+
 export const useClash = () => {
   const { data: clash, refetch } = useRuntimeConfig()