Refactor process picker into palette pattern, add notification app picker

- Refactor process-picker.ts into generic NamePalette with two concrete
  instances: ProcessPalette (running processes) and NotificationAppPalette
  (OS notification history apps)
- Notification color strip app colors and filter list now use
  NotificationAppPalette (shows display names like "Telegram" instead of
  process names like "telegram.exe")
- Fix case-insensitive matching for app_colors and app_filter_list in
  notification_stream.py
- Compact browse/remove buttons in notification app color rows with
  proper search icon
- Remove old inline process-picker HTML/CSS (replaced by palette overlay)

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

server/src/wled_controller/static/css/modal.css

@@ -1403,8 +1403,8 @@
 }
 
 .notif-app-color-row .notif-app-color {
-    width: 36px;
-    height: 32px;
+    width: 28px;
+    height: 28px;
     border: 1px solid var(--border-color);
     border-radius: 4px;
     padding: 1px;
@@ -1413,14 +1413,40 @@
     flex-shrink: 0;
 }
 
+.notif-app-browse,
 .notif-app-color-remove {
-    font-size: 0.7rem;
-    padding: 0 4px;
+    background: none;
+    border: 1px solid var(--border-color);
+    color: var(--text-muted);
+    border-radius: 4px;
+    cursor: pointer;
+    padding: 0;
+    width: 28px;
+    height: 28px;
     min-width: unset;
-    height: 32px;
+    display: inline-flex;
+    align-items: center;
+    justify-content: center;
+    flex-shrink: 0;
+    transition: border-color 0.2s, color 0.2s;
+}
+
+.notif-app-browse svg {
+    width: 14px;
+    height: 14px;
+}
+
+.notif-app-color-remove {
+    font-size: 0.75rem;
     line-height: 1;
 }
 
+.notif-app-browse:hover,
+.notif-app-color-remove:hover {
+    border-color: var(--primary-color);
+    color: var(--text-color);
+}
+
 /* ── Notification history list ─────────────────────────────────── */
 
 .notif-history-row {