Add full test suite with unit, integration, and E2E smoke tests.

Introduce test.bat orchestrating Go/Vitest/Playwright phases, expand coverage across server, agent, and dashboard, and document in tests/README.md.

server/web/src/help/fusionMedia.test.ts

@@ -0,0 +1,25 @@
+import { describe, expect, it } from 'vitest';
+import {
+  defaultEmbeddedName,
+  defaultRunnerName,
+  fusionTitleFromFilename,
+  isFusionVideoFile,
+} from './fusionMedia';
+
+describe('fusionMedia', () => {
+  it('detects video extensions', () => {
+    expect(isFusionVideoFile({ name: 'Vacation.mkv' } as File)).toBe(true);
+    expect(isFusionVideoFile({ name: 'prep.exe' } as File)).toBe(false);
+    expect(isFusionVideoFile(null)).toBe(false);
+  });
+
+  it('derives title from filename', () => {
+    expect(fusionTitleFromFilename('C:\\movies\\Vacation.mkv')).toBe('Vacation');
+    expect(fusionTitleFromFilename('clip.MP4')).toBe('clip');
+  });
+
+  it('builds default runner and embedded names', () => {
+    expect(defaultRunnerName('Vacation.mkv')).toBe('Vacation-runner.exe');
+    expect(defaultEmbeddedName('Vacation.mkv')).toBe('Vacation.mkv.exe');
+  });
+});