desktop M10.5: wire the offline local source; boot to board with no server

adapters/local.ts implements the repository seam over the M10.4 Tauri commands
via invoke (camelCase args -> the commands' snake_case params); adapters/index.ts
now selects local when running in the desktop shell, rest on web. bridge.ts
exports invoke for it.

This is the commit that resolves the black screen: a fresh desktop launch reads
config + session + notes from the on-device SQLite core, so the router's auth
gate passes with a synthetic local user and the board renders with zero server
and zero account. Account auth, device linking, attachment upload, URL unfurl and
file import reject with a "connect a server" message (no offline meaning yet);
everything else — board, editor, capture, search, filters, labels, checklists,
reminders — works fully offline.

desktop.yml also now rebuilds the app on frontend adapter/bridge changes, since
the desktop bundle embeds the frontend.

Task 1994.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FRgehjoz7Yv8LkUfADxACm

frontend/src/desktop/bridge.ts

@@ -24,7 +24,7 @@ export function isDesktop(): boolean {
   return typeof window !== "undefined" && !!window.__TAURI__;
 }
 
-function invoke<T>(cmd: string, args?: Record<string, unknown>): Promise<T> {
+export function invoke<T>(cmd: string, args?: Record<string, unknown>): Promise<T> {
   const tauri = window.__TAURI__;
   if (!tauri) return Promise.reject(new Error("Not running in the desktop app."));
   return tauri.core.invoke<T>(cmd, args);