@: directories complete, not just files

walk({includeDirs}) yields src/ and src/ui/ with trailing slash, only
on the @ path. matchPaths ranks dirs before files for the same prefix
so @src/ surfaces the directory itself. Insertion keeps the slash.

test/complete-dirs.test.ts

@@ -0,0 +1,64 @@
+import { expect, test } from 'bun:test';
+import { mkdirSync, mkdtempSync, rmSync } from 'node:fs';
+import { tmpdir } from 'node:os';
+import { join } from 'node:path';
+import { walk } from '../src/ignore';
+import { matchPaths, completePath, pathToken } from '../src/complete';
+
+test('walk includeDirs yields directories with trailing slash', async () => {
+  const dir = mkdtempSync(join(tmpdir(), 'shiro-dirs-'));
+  const orig = process.cwd();
+  try {
+    process.chdir(dir);
+    await Bun.write('a.ts', '');
+    mkdirSync('src/ui', { recursive: true });
+    await Bun.write('src/ui/App.tsx', '');
+    await Bun.write('src/session.ts', '');
+
+    const out: string[] = [];
+    for await (const p of walk({ includeDirs: true })) out.push(p);
+    expect(out).toContain('src/');
+    expect(out).toContain('src/ui/');
+    expect(out).toContain('src/session.ts');
+    expect(out).toContain('a.ts');
+  } finally {
+    process.chdir(orig);
+    rmSync(dir, { recursive: true, force: true });
+  }
+});
+
+test('walk without includeDirs still file-only (existing behaviour)', async () => {
+  const dir = mkdtempSync(join(tmpdir(), 'shiro-nodirs-'));
+  const orig = process.cwd();
+  try {
+    process.chdir(dir);
+    mkdirSync('src', { recursive: true });
+    await Bun.write('src/a.ts', '');
+    const out: string[] = [];
+    for await (const p of walk()) out.push(p);
+    expect(out).not.toContain('src/');
+    expect(out).toContain('src/a.ts');
+  } finally {
+    process.chdir(orig);
+    rmSync(dir, { recursive: true, force: true });
+  }
+});
+
+test('matchPaths surfaces dirs for a directory prefix and keeps trailing slash through completion', () => {
+  const paths = ['src/', 'src/ui/', 'src/ui/App.tsx', 'src/session.ts', 'README.md'];
+  const hits = matchPaths(paths, 'src/');
+  expect(hits).toContain('src/');
+  expect(hits).toContain('src/ui/');
+  // dirs rank before files for the same prefix
+  expect(hits.indexOf('src/ui/')).toBeLessThan(hits.indexOf('src/ui/App.tsx'));
+
+  // inserted dir keeps trailing slash and trailing space
+  const tok = pathToken('@src/u', 6)!;
+  const { value } = completePath('@src/u', tok, 'src/ui/');
+  expect(value).toBe('src/ui/ ');
+});
+
+test('matchPaths with empty query prefers dirs', () => {
+  const hits = matchPaths(['src/', 'a.ts', 'src/ui/', 'b.ts'], '', 3);
+  expect(hits[0]).toBe('src/');
+});