Polish: npm test runs every test file, two silent failures now log, Loading placeholders shimmer

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

public/signal-view.js

@@ -64,7 +64,7 @@ function viewSignal(args = []) { sg.cur = args[0] || null; sgDockHide(); return
 async function sgMount(root, dock) {
   sg.inChat = false; // (a full Signal screen or the floating panel; Chat sets this itself when it shows a Signal conversation)
   sg.root = root; sg.dock = dock; const cls = dock ? 'sgdockin' : 'wrap sgwrap', title = dock ? '' : `<h1>Signal</h1>${typeof sgInChat === 'function' && sgInChat() ? `<p class="sub" style="margin:0 0 8px"><a href="#/chat" style="color:var(--accent)">‹ Back to Chat</a> · your Signal chats are also listed there</p>` : ''}`;
-  root.innerHTML = `<div class="${cls}">${title}<p class="empty">Loading…</p></div>`;
+  root.innerHTML = `<div class="${cls}">${title}<p class="empty loading" role="status">Loading…</p></div>`;
   let st; try { st = await sgApi('/status'); } catch (e) { root.innerHTML = `<div class="${cls}">${title}<p class="err">${esc(e.message)}</p></div>`; return; }
   if (sg.root !== root) return; sg.st = st;
   if (!st.reachable) { root.innerHTML = `<div class="${cls}">${title}<div class="card" style="max-width:none"><p style="margin-top:0">The Signal service is not answering. Check that its container (<b>signal</b>) is running, then reload.</p></div></div>`; return; }