feat: add Tauri state persistence and BvCli trait

- Add Tauri storage adapter for Zustand (tauri-storage.ts)
- Add read_state, write_state, clear_state Tauri commands
- Wire focus-store and nav-store to use Tauri persistence
- Add BvCli trait for bv CLI mocking with response types
- Add BvError and McError conversion for bv errors
- Add cleanup_tmp_files tests for bridge
- Fix linter-introduced tauri_specta::command issues

Closes bd-2x6, bd-gil, bd-3px

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/stores/focus-store.ts

@@ -6,7 +6,8 @@
  */
 
 import { create } from "zustand";
-import { persist } from "zustand/middleware";
+import { persist, createJSONStorage } from "zustand/middleware";
+import { getStorage } from "@/lib/tauri-storage";
 import type { FocusAction, FocusItem } from "@/lib/types";
 
 export interface FocusState {
@@ -108,6 +109,7 @@ export const useFocusStore = create<FocusState>()(
     }),
     {
       name: "mc-focus-store",
+      storage: createJSONStorage(() => getStorage()),
       partialize: (state) => ({
         current: state.current,
         queue: state.queue,

src/stores/nav-store.ts

@@ -6,7 +6,8 @@
  */
 
 import { create } from "zustand";
-import { persist } from "zustand/middleware";
+import { persist, createJSONStorage } from "zustand/middleware";
+import { getStorage } from "@/lib/tauri-storage";
 
 export type ViewId = "focus" | "queue" | "inbox";
 
@@ -23,6 +24,7 @@ export const useNavStore = create<NavState>()(
     }),
     {
       name: "mc-nav-store",
+      storage: createJSONStorage(() => getStorage()),
     }
   )
 );