diff --git a/src/__tests__/it-stage-and-commit.test.ts b/src/__tests__/it-stage-and-commit.test.ts
new file mode 100644
index 0000000..496b7bd
--- /dev/null
+++ b/src/__tests__/it-stage-and-commit.test.ts
@@ -0,0 +1,85 @@
+/**
+ * Integration test for stageAndCommit
+ *
+ * Tests that gitignored files are NOT included in commits.
+ * Regression test for c89ac4c where `git add -f .takt/reports/` caused
+ * gitignored report files to be committed.
+ */
+
+import { describe, it, expect, beforeEach, afterEach } from 'vitest';
+import { mkdirSync, writeFileSync, rmSync, existsSync } from 'node:fs';
+import { join } from 'node:path';
+import { execFileSync } from 'node:child_process';
+import { tmpdir } from 'node:os';
+import { stageAndCommit } from '../infra/task/git.js';
+
+describe('stageAndCommit', () => {
+  let testDir: string;
+
+  beforeEach(() => {
+    testDir = join(tmpdir(), `takt-test-${Date.now()}`);
+    mkdirSync(testDir, { recursive: true });
+
+    execFileSync('git', ['init'], { cwd: testDir });
+    execFileSync('git', ['config', 'user.name', 'Test User'], { cwd: testDir });
+    execFileSync('git', ['config', 'user.email', 'test@example.com'], { cwd: testDir });
+
+    // Initial commit
+    writeFileSync(join(testDir, 'README.md'), '# Test');
+    execFileSync('git', ['add', '.'], { cwd: testDir });
+    execFileSync('git', ['commit', '-m', 'Initial commit'], { cwd: testDir });
+  });
+
+  afterEach(() => {
+    if (existsSync(testDir)) {
+      rmSync(testDir, { recursive: true, force: true });
+    }
+  });
+
+  it('should not commit gitignored .takt/reports/ files', () => {
+    // Setup: .takt/ is gitignored
+    writeFileSync(join(testDir, '.gitignore'), '.takt/\n');
+    execFileSync('git', ['add', '.gitignore'], { cwd: testDir });
+    execFileSync('git', ['commit', '-m', 'Add gitignore'], { cwd: testDir });
+
+    // Create .takt/reports/ with a report file
+    mkdirSync(join(testDir, '.takt', 'reports', 'test-report'), { recursive: true });
+    writeFileSync(join(testDir, '.takt', 'reports', 'test-report', '00-plan.md'), '# Plan');
+
+    // Also create a tracked file change to ensure commit happens
+    writeFileSync(join(testDir, 'src.ts'), 'export const x = 1;');
+
+    const hash = stageAndCommit(testDir, 'test commit');
+    expect(hash).toBeDefined();
+
+    // Verify .takt/reports/ is NOT in the commit
+    const committedFiles = execFileSync('git', ['diff-tree', '--no-commit-id', '-r', '--name-only', 'HEAD'], {
+      cwd: testDir,
+      encoding: 'utf-8',
+      stdio: 'pipe',
+    }).trim();
+
+    expect(committedFiles).toContain('src.ts');
+    expect(committedFiles).not.toContain('.takt/reports/');
+  });
+
+  it('should commit normally when no gitignored files exist', () => {
+    writeFileSync(join(testDir, 'app.ts'), 'console.log("hello");');
+
+    const hash = stageAndCommit(testDir, 'add app');
+    expect(hash).toBeDefined();
+
+    const committedFiles = execFileSync('git', ['diff-tree', '--no-commit-id', '-r', '--name-only', 'HEAD'], {
+      cwd: testDir,
+      encoding: 'utf-8',
+      stdio: 'pipe',
+    }).trim();
+
+    expect(committedFiles).toBe('app.ts');
+  });
+
+  it('should return undefined when there are no changes', () => {
+    const hash = stageAndCommit(testDir, 'empty');
+    expect(hash).toBeUndefined();
+  });
+});