feat: wire autoFix into PostToolUse hook flow (Task 5)

Add auto-fix lint/test check after existing PostToolUse hooks in
runPostToolUseHooks. When autoFix is configured in settings, runs
lint/test commands after file_edit/file_write tools and yields
errors as hook_additional_context for the model to act on.

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

src/services/autoFix/autoFixIntegration.test.ts

@@ -0,0 +1,46 @@
+import { describe, expect, test } from 'bun:test'
+import { getAutoFixConfig } from './autoFixConfig.js'
+import { shouldRunAutoFix, buildAutoFixContext } from './autoFixHook.js'
+import { runAutoFixCheck } from './autoFixRunner.js'
+
+describe('autoFix end-to-end flow', () => {
+  test('full flow: config → shouldRun → check → context', async () => {
+    const config = getAutoFixConfig({
+      enabled: true,
+      lint: 'echo "error: unused" && exit 1',
+      maxRetries: 2,
+      timeout: 5000,
+    })
+    expect(config).not.toBeNull()
+    expect(shouldRunAutoFix('file_edit', config)).toBe(true)
+
+    const result = await runAutoFixCheck({
+      lint: config!.lint,
+      test: config!.test,
+      timeout: config!.timeout,
+      cwd: '/tmp',
+    })
+    expect(result.hasErrors).toBe(true)
+
+    const context = buildAutoFixContext(result)
+    expect(context).not.toBeNull()
+    expect(context).toContain('AUTO-FIX')
+    expect(context).toContain('unused')
+  })
+
+  test('full flow: no errors = no context', async () => {
+    const config = getAutoFixConfig({
+      enabled: true,
+      lint: 'echo "all clean"',
+      timeout: 5000,
+    })
+    const result = await runAutoFixCheck({
+      lint: config!.lint,
+      timeout: config!.timeout,
+      cwd: '/tmp',
+    })
+    expect(result.hasErrors).toBe(false)
+    const context = buildAutoFixContext(result)
+    expect(context).toBeNull()
+  })
+})