refactor(decnet_web/CanaryTokens): extract list views

Lift the three tab bodies — tokens, blobs, file drops — into
their own files. Each takes plain props (data + the operations
its rows need), so the page shell stops mixing tab markup with
data plumbing.

- New CanaryTokens/TokenListView.tsx (text search + state/scope
  filter selectors + flat row grid; visibleTokens memo lives here
  now). Exports StateFilter / ScopeFilter union types so the page
  can declare its filter useState with the right shape.
- New CanaryTokens/BlobListView.tsx (delete refused while a token
  references a blob; ref count badge reuses the disabled button).
- New CanaryTokens/FileDropListView.tsx (CLEAR LIST hidden when
  the local log is empty).
- Three companion tests cover empty states, filter behavior,
  delete refused-vs-allowed, and the per-tab callback wiring.

Wiring into CanaryTokens.tsx + the hook lands next.

decnet_web/src/components/CanaryTokens/FileDropListView.test.tsx

@@ -0,0 +1,48 @@
+import { describe, it, expect, vi } from 'vitest';
+import { render, screen } from '@testing-library/react';
+import userEvent from '@testing-library/user-event';
+import { FileDropListView } from './FileDropListView';
+import type { FileDropEntry } from './FileDropModal';
+
+const entry = (overrides: Partial<FileDropEntry> = {}): FileDropEntry => ({
+  id: 'fd-1',
+  decky_name: 'decoy-99',
+  topology_id: null,
+  path: '/tmp/payload.bin',
+  size_bytes: 4096,
+  filename: 'payload.bin',
+  mode: 0o644,
+  mtime_offset: 0,
+  dropped_at: '2026-05-09T11:00:00Z',
+  ...overrides,
+});
+
+describe('FileDropListView', () => {
+  it('shows the empty hint when fileDrops is []', () => {
+    render(<FileDropListView fileDrops={[]} onClear={() => {}} />);
+    expect(screen.getByText(/No file drops in this browser yet/)).toBeInTheDocument();
+  });
+
+  it('hides CLEAR LIST when there are no entries', () => {
+    render(<FileDropListView fileDrops={[]} onClear={() => {}} />);
+    expect(screen.queryByText('CLEAR LIST')).not.toBeInTheDocument();
+  });
+
+  it('renders one row per drop with its path + decky name', () => {
+    render(
+      <FileDropListView fileDrops={[entry()]} onClear={() => {}} />,
+    );
+    expect(screen.getByText('decoy-99')).toBeInTheDocument();
+    expect(screen.getByText('/tmp/payload.bin')).toBeInTheDocument();
+  });
+
+  it('CLEAR LIST invokes onClear', async () => {
+    const onClear = vi.fn();
+    const user = userEvent.setup();
+    render(
+      <FileDropListView fileDrops={[entry()]} onClear={onClear} />,
+    );
+    await user.click(screen.getByText('CLEAR LIST'));
+    expect(onClear).toHaveBeenCalled();
+  });
+});