refactor: simplify hook execution - use Node directly instead of Bun (#290)

Removes bun-wrapper indirection. Hooks are compiled JavaScript that work perfectly with Node. Worker still uses Bun where performance matters. Fixes #264

tests/bun-path.test.ts

@@ -0,0 +1,101 @@
+import { describe, it, expect, vi } from 'vitest';
+import { existsSync } from 'fs';
+import { spawnSync } from 'child_process';
+
+// Mock the dependencies
+vi.mock('fs', () => ({
+  existsSync: vi.fn()
+}));
+
+vi.mock('child_process', () => ({
+  spawnSync: vi.fn()
+}));
+
+// Import after mocking
+import { getBunPath, isBunAvailable, getBunPathOrThrow } from '../src/utils/bun-path';
+
+describe('bun-path utility', () => {
+  it('should return "bun" when available in PATH', () => {
+    // Mock successful bun --version check
+    vi.mocked(spawnSync).mockReturnValue({
+      status: 0,
+      stdout: Buffer.from('1.0.0'),
+      stderr: Buffer.from(''),
+      pid: 1234,
+      output: [],
+      signal: null
+    } as any);
+
+    const result = getBunPath();
+    expect(result).toBe('bun');
+    expect(spawnSync).toHaveBeenCalledWith('bun', ['--version'], expect.any(Object));
+  });
+
+  it('should check common installation paths when not in PATH', () => {
+    // Mock failed PATH check
+    vi.mocked(spawnSync).mockReturnValue({
+      status: 1,
+      stdout: Buffer.from(''),
+      stderr: Buffer.from(''),
+      pid: 1234,
+      output: [],
+      signal: null
+    } as any);
+
+    // Mock existsSync to return true for ~/.bun/bin/bun
+    vi.mocked(existsSync).mockImplementation((path: any) => {
+      return path.includes('.bun/bin/bun');
+    });
+
+    const result = getBunPath();
+    expect(result).toContain('.bun/bin/bun');
+  });
+
+  it('should return null when bun is not found anywhere', () => {
+    // Mock failed PATH check
+    vi.mocked(spawnSync).mockReturnValue({
+      status: 1,
+      stdout: Buffer.from(''),
+      stderr: Buffer.from(''),
+      pid: 1234,
+      output: [],
+      signal: null
+    } as any);
+
+    // Mock existsSync to always return false
+    vi.mocked(existsSync).mockReturnValue(false);
+
+    const result = getBunPath();
+    expect(result).toBeNull();
+  });
+
+  it('should return true for isBunAvailable when bun is found', () => {
+    // Mock successful bun check
+    vi.mocked(spawnSync).mockReturnValue({
+      status: 0,
+      stdout: Buffer.from('1.0.0'),
+      stderr: Buffer.from(''),
+      pid: 1234,
+      output: [],
+      signal: null
+    } as any);
+
+    const result = isBunAvailable();
+    expect(result).toBe(true);
+  });
+
+  it('should throw error in getBunPathOrThrow when bun not found', () => {
+    // Mock failed bun check
+    vi.mocked(spawnSync).mockReturnValue({
+      status: 1,
+      stdout: Buffer.from(''),
+      stderr: Buffer.from(''),
+      pid: 1234,
+      output: [],
+      signal: null
+    } as any);
+    vi.mocked(existsSync).mockReturnValue(false);
+
+    expect(() => getBunPathOrThrow()).toThrow('Bun is required');
+  });
+});