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/js/modules/tasks.js

@@ -13,8 +13,13 @@ const summary = $('tasks-summary');
 const countBadge = $('tasks-open-count');
 
 function collectTasks() {
+    const showShopping = localStorage.getItem('hyprcrd-tasks-show-shopping') === '1';
     const all = [];
     for (const card of state.cards) {
+        if (!showShopping) {
+            const tags = (card.tags || '').split(',').map(s => s.trim());
+            if (tags.includes('einkauf') || tags.includes('shopping')) continue;
+        }
         const re = /- \[([ xX])\][ \t]*([^\n\r]*)/g;
         let m, idx = 0;
         while ((m = re.exec(card.body || '')) !== null) {