relay UI overhaul, favicon, settings, admin last-seen, fixes

Relay:
  - Inbox/shared/sent split into own view-inbox (nav button + poll).
    Compose is now single-column, centered.
  - Header logo links to compose. Inbox badge stays fresh on all
    views via a quiet loadInbox on every view switch.
  - Mobile menu: full-height sheet below header, larger buttons
    (15px font, 14px padding), full width.
  - Login form wrapped in <form> with name attributes + for/id on
    labels so password managers can autofill.
  - Admin user list shows "last seen <relative time>" per user.
    last_seen_at column on tenants, updated on every authenticated
    request (session + client API).
  - Cache-busting on style.css + app.js via filemtime.
  - View persistence in localStorage (survives reload).
  - Shared-bucket cards show title only (preview line removed).

Favicon:
  - favicon.svg added to project root + copied to public/, relay/,
    website/. Linked via <link rel="icon" type="image/svg+xml"> in
    all three <head> sections.

Settings:
  - New toggle: "Show shopping list items in task collector"
    (default off). collectTasks skips #einkauf/#shopping cards when
    disabled.

Fixes:
  - card-spinner gets display:inline-block so it rotates outside
    flex containers (shopping save spinner).
  - Tim tab test opens the plugin before checking active state.
  - Compose view centered with margin:auto on desktop.

Bumps to 1.9.29.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

public/plugins/shopping/shopping.js

@@ -241,7 +241,7 @@ function openDialog() {
         const prev = getActiveIds();
         const next = [...selected];
         setActiveIds(next);
-        status.textContent = 'saving…';
+        status.innerHTML = '<i class="ph ph-spinner card-spinner" style="font-size:14px;vertical-align:middle;margin-right:4px;"></i> saving — please wait!';
         try {
             // Remove deactivated lists from relay.
             for (const id of prev) {

public/plugins/tests/tim.test.js

@@ -127,7 +127,9 @@ describe('Tim Plugin: Open & Close', () => {
 describe('Tim Plugin: Tabs', () => {
     afterEach(async () => { closeTim(); await closeAll(); });
 
-    it('duration tab is active on load', () => {
+    it('duration tab is active on load', async () => {
+        openTim();
+        await sleep(30);
         const tab = document.querySelector('.tim-tab[data-tim-tab="duration"]');
         expect(tab.classList.contains('active')).toBe(true);
     });