feat: autolink URLs in list items, link picker, and inline edit

- Add autolink Jinja2 filter to detect URLs and make them clickable
- Add link picker dropdown to insert existing link URLs into list item content
- Add inline edit with link picker on each list item row
- Apply autolink filter on list detail and focus available list items

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

static/style.css

@@ -1144,6 +1144,53 @@ a:hover { color: var(--accent-hover); }
 }
 .grip-btn:hover { color: var(--accent); }
 
+/* ---- Link Picker & Inline Edit ---- */
+.link-picker {
+    padding: 4px 8px;
+    font-size: 0.8rem;
+    background: var(--surface2);
+    color: var(--muted);
+    border: 1px solid var(--border);
+    border-radius: var(--radius);
+    cursor: pointer;
+}
+.link-picker:hover { border-color: var(--accent); color: var(--text); }
+
+.inline-edit-form {
+    flex: 1;
+    display: flex;
+    align-items: center;
+    gap: 6px;
+    min-width: 0;
+}
+.inline-edit-form input[type="text"] {
+    flex: 1;
+    min-width: 0;
+    padding: 4px 8px;
+    font-size: 0.85rem;
+    background: var(--surface2);
+    color: var(--text);
+    border: 1px solid var(--border);
+    border-radius: var(--radius);
+}
+.inline-edit-form input[type="text"]:focus {
+    border-color: var(--accent);
+    outline: none;
+}
+
+/* ---- Autolinked URLs in list items ---- */
+.autolink {
+    color: var(--accent);
+    text-decoration: underline;
+    text-decoration-color: var(--accent-soft);
+    text-underline-offset: 2px;
+    transition: text-decoration-color var(--transition);
+}
+.autolink:hover {
+    text-decoration-color: var(--accent);
+    color: var(--accent);
+}
+
 /* ---- Scrollbar ---- */
 ::-webkit-scrollbar { width: 6px; }
 ::-webkit-scrollbar-track { background: transparent; }