fix: mobile layout, task clicks, list tab corners, hashtags in URLs

Mobile
- Plus button in triage did nothing: the stored action returned the
  capture function instead of calling it
- Workspace: tabs share the full width; save status sits as an icon next
  to the note title instead of wrapping into its own row; "Neue Notiz" /
  "Neuer Ordner" only in the top menu (and +), not repeated in the list
- Outliner fields measured while hidden stayed one line high (cut-off
  callout); they are measured again when their width changes
- Task dialog: scrolls in a div instead of a fieldset, height in dvh,
  notes editor grows with its text, so long notes are fully reachable

Desktop
- Delete button of the selected task/shopping list sits inside the tab as
  its own rounded button (matches rounded themes like Soft)

Both
- Tasks sometimes did not open: every reload after an action replaced the
  list with a loading placeholder, swallowing clicks; reloads are now
  silent after the first load of a list, stale responses are dropped
- Hashtags need whitespace or "(" before "#", so URL anchors are no
  longer tags (server, browser); one-time cleanup of stored anchor tags

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

frontend/src/lib/__tests__/hashtags.test.ts

@@ -0,0 +1,13 @@
+import { describe, it, expect } from 'vitest';
+import { extractHashtags } from '../hashtags';
+
+describe('extractHashtags', () => {
+  it('finds tags at the start, after spaces and after "("', () => {
+    expect(extractHashtags('#start mitten #zwei (#drei)')).toEqual(['start', 'zwei', 'drei']);
+  });
+
+  it('ignores URL anchors and words like C#', () => {
+    expect(extractHashtags('example.com/blog#ueberschrift')).toEqual([]);
+    expect(extractHashtags('https://x.de/#anker und #echt, C# nicht')).toEqual(['echt']);
+  });
+});