feat: detect new web builds + hard-refresh escape hatch (0.1.17/batch78)

Root cause of "the fix works on mobile but not on desktop/web": nothing was wrong with
the code — the desktop app now CLOSES TO TRAY, so it can run for weeks on the page it
loaded on day one and never re-fetch after a deploy. There was also no way to force it
off a stale page (no menu bar → no reload accelerator).

- Server: GET /api/build returns home.html's __BUILD marker.
- Client: polls it (boot, on focus/visibility, every 10 min); when the server's build
  differs from the running one, shows a branded "A new version is available — Refresh"
  banner. Settings gains an always-available "Refresh app" with the current build shown.
- hardReloadApp(): in the browser it unregisters service workers + clears CacheStorage
  then reloads cache-busted; in the shell it calls the native hard reload.
- Desktop: hard-reload IPC (clears the session HTTP cache + reloadIgnoringCache), wired to
  Ctrl+R (reload), Ctrl+Shift+R / F5 (hard reload), and a "Refresh app (get latest)" tray
  item. Previously there was literally no way to clear the cache from the app.

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

desktop/main.js

@@ -83,6 +83,17 @@ function avatarToTempPng(src) {
   });
 }
 
+// ---- Hard refresh -------------------------------------------------------------------------------
+// The app closes to TRAY, so it can run for weeks on the page it first loaded and never see a new web
+// deploy. This clears the shell's HTTP cache and reloads ignoring cache, so a stale UI is always
+// recoverable. Reachable from: the in-app "Refresh" banner / Settings, Ctrl+R (reload),
+// Ctrl+Shift+R or F5 (hard reload), and the tray menu.
+async function hardReloadWin() {
+  try { await session.fromPartition('persist:bizconnect').clearCache(); } catch (_) {}
+  try { if (win && !win.isDestroyed()) win.webContents.reloadIgnoringCache(); } catch (_) {}
+}
+ipcMain.handle('hard-reload', async () => { await hardReloadWin(); return true; });
+
 // ---- Remote control: OS input injection for a screen the local user is SHARING ----
 // The renderer (share flow) forwards a viewer's mouse/keyboard events here for injection. Injection is
 // HARD-GATED behind an explicit consent flag (rcArmed): nothing is injected until the local user clicks
@@ -207,6 +218,7 @@ function createTray() {
     const showApp = () => { if (!win) return createWindow(); if (win.isMinimized()) win.restore(); win.show(); win.focus(); };
     tray.setContextMenu(Menu.buildFromTemplate([
       { label: 'Open Biz Connect', click: showApp },
+      { label: 'Refresh app (get latest)', click: () => { showApp(); hardReloadWin(); } },
       { type: 'separator' },
       { label: 'Quit', click: () => { isQuitting = true; app.quit(); } },
     ]));
@@ -257,6 +269,19 @@ function createWindow() {
   win.once('ready-to-show', reveal);
   setTimeout(reveal, 12000);
 
+  // The menu bar is hidden, so the usual reload accelerators don't exist — wire them by hand. Without
+  // these there was literally no way to force the app off a stale page.
+  win.webContents.on('before-input-event', (e, input) => {
+    if (input.type !== 'keyDown') return;
+    const k = String(input.key || '').toLowerCase();
+    const mod = input.control || input.meta;
+    if ((mod && k === 'r') || k === 'f5') {
+      e.preventDefault();
+      if (input.shift || k === 'f5') hardReloadWin();           // hard: clear cache + reload
+      else { try { win.webContents.reload(); } catch (_) {} }   // plain reload
+    }
+  });
+
   // Close = hide to tray (keep running for notifications). First time, tell the user where it went.
   let toldTray = false;
   win.on('close', (e) => {