fix(desktop): allow pick_directory command in ACL

The import-memory button failed with "Command pick_directory not allowed
by ACL" because Tauri v2 requires custom commands to be granted in the
capability. Add allow-pick-directory permission and grant it.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

frontends/desktop/src-tauri/capabilities/default.json

@@ -18,6 +18,7 @@
     "allow-start-bridge-with-config",
     "allow-get-config",
     "allow-export-mykey",
+    "allow-pick-directory",
     "allow-shortcut-should-ask",
     "allow-shortcut-decide"
   ]

frontends/desktop/src-tauri/permissions/bridge-commands.toml

@@ -18,6 +18,11 @@ identifier = "allow-export-mykey"
 description = "Save mykey.py via native file dialog."
 commands.allow = ["export_mykey"]
 
+[[permission]]
+identifier = "allow-pick-directory"
+description = "Pick a source directory via native folder dialog (import memory)."
+commands.allow = ["pick_directory"]
+
 [[permission]]
 identifier = "allow-shortcut-should-ask"
 description = "Check whether to show the first-run desktop-shortcut prompt."