Fix stale PWA service worker after updates; collapsible task list; short screens

Installed apps checked their service worker at /sw-<old build>.js. That file no
longer exists after an update and the static fallback answered with index.html,
so the update check failed and the old worker kept serving the previous app
shell. The old frontend crashed on the new image references (base64Size of a
missing `data`), leaving a blank page on phones. Old service worker URLs now get
the clean-up worker (/sw.js), which unregisters and reloads; missing scripts and
styles answer 404 instead of HTML.

- Task list above the composer folds to one line (progress, current task),
  remembered per device.
- max-height: 560px layout (square phones such as the Clicks Communicator,
  landscape): tighter top bar, composer and new-chat wizard.

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

web/src/styles.css

@@ -721,6 +721,39 @@ button.session-group:hover {
   margin: 8px 0;
   font-size: 13px;
 }
+.todos-head {
+  display: flex;
+  align-items: center;
+  gap: 6px;
+  width: 100%;
+  min-width: 0;
+  padding: 0;
+  background: none;
+  border: none;
+  color: var(--muted);
+  font: inherit;
+  font-size: 12px;
+  text-align: left;
+  cursor: pointer;
+}
+.todos-head:hover {
+  color: var(--fg1);
+}
+.todos-count {
+  font-variant-numeric: tabular-nums;
+}
+.todos-current {
+  flex: 1;
+  min-width: 0;
+  overflow: hidden;
+  white-space: nowrap;
+  text-overflow: ellipsis;
+  color: var(--accent);
+  font-weight: 600;
+}
+.todos.collapsed {
+  padding-block: 6px;
+}
 .todos ul {
   list-style: none;
   padding: 0;
@@ -3773,3 +3806,104 @@ span.chat-tab > button {
 .instructions-modal {
   width: min(640px, calc(100vw - 32px));
 }
+
+/* --- short screens ----------------------------------------------------------
+ * Square phones (e.g. Clicks Communicator, ~393x400 CSS px with a hardware
+ * keyboard) and phones in landscape: height is the scarce dimension, so bars,
+ * the composer and the new-chat wizard get tighter and the chat keeps the room. */
+@media (max-height: 560px) {
+  .topbar {
+    min-height: 40px;
+    padding: 4px 10px;
+    padding-top: max(4px, env(safe-area-inset-top));
+    gap: 4px;
+  }
+  .topbar button.ghost {
+    padding: 4px 6px;
+  }
+  .chat {
+    padding: 10px 12px 14px;
+  }
+  .msg {
+    margin-bottom: 10px;
+  }
+  .composer-wrap {
+    padding: 6px 10px;
+    padding-bottom: max(6px, env(safe-area-inset-bottom));
+  }
+  .composer textarea {
+    min-height: 38px;
+    max-height: 30vh;
+    padding: 8px 10px;
+  }
+  /* One placeholder line instead of two (the textarea grows with its content). */
+  .composer textarea::placeholder {
+    white-space: nowrap;
+    overflow: hidden;
+    text-overflow: ellipsis;
+  }
+  .composer-bar {
+    margin-top: 4px;
+    gap: 4px;
+  }
+  .composer-bar select {
+    max-width: 150px;
+    padding: 2px 4px;
+  }
+  .composer-actions button {
+    padding: 4px 10px;
+  }
+  .todos {
+    margin: 4px 0;
+    padding: 6px 10px;
+  }
+  .page {
+    padding: 12px;
+  }
+  .wiz-title {
+    font-size: 19px;
+    margin: 0 0 8px;
+  }
+  .wiz-sub {
+    display: none;
+  }
+  .wiz-panel {
+    padding: 12px;
+  }
+  .wiz-step {
+    margin-bottom: 16px;
+  }
+  .wiz-step h3 {
+    font-size: 16px;
+    margin-bottom: 8px;
+  }
+  .wiz-cards,
+  .wiz-cards.five {
+    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
+    gap: 8px;
+  }
+  .wiz-card {
+    padding: 8px 10px;
+    gap: 8px;
+    min-height: 44px;
+    font-size: 14px;
+  }
+  .wiz-card.active {
+    padding: 7px 9px;
+  }
+  .wiz-card-text {
+    padding-right: 14px;
+  }
+  .wiz-card-desc {
+    display: none;
+  }
+  .wiz-icon {
+    width: 20px;
+    height: 20px;
+  }
+  .wiz-num {
+    width: 24px;
+    height: 24px;
+    font-size: 12px;
+  }
+}