drive workspace ignore from ignore_files:, add files.walk

Replace the hardcoded .gitignore + .clideignore read with the ordered
ignore_files: chain from .pql/config.yaml (D-4) — the single ignore
knob clide owns (D-3). readIgnoreFiles defaults to .gitignore (plus
.clideignore when present) when the config is absent or malformed, and
honours an explicit [] as "no file-based exclusions".

Add walkFiles + the files.walk command: a recursive, ignore-pruned,
capped flat file listing reused by quick-open (T-51) and the search
engine (T-52). Closes the never-filed ignore-layering placeholder in
files_commands.dart.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

test/daemon/files_commands_test.dart

@@ -73,6 +73,17 @@ void main() {
     expect(names, ['main.dart']);
   });
 
+  test('files.walk returns a flat, recursive file list (no dirs, no ignored)', () async {
+    final r = await call('files.walk', const {});
+    expect(r.ok, isTrue);
+    final paths = (r.data['files'] as List).cast<String>();
+    expect(paths, containsAll(['README.md', 'pubspec.yaml', 'lib/main.dart']));
+    // Directories themselves are never emitted, and .dart_tool is pruned.
+    expect(paths, isNot(contains('lib')));
+    expect(paths.any((p) => p.startsWith('.dart_tool')), isFalse);
+    expect(r.data['truncated'], isFalse);
+  });
+
   test('files.watch acks subscription', () async {
     final r = await call('files.watch', const {});
     expect(r.ok, isTrue);

test/files/pql_config_test.dart

@@ -0,0 +1,63 @@
+/// Tests for `readIgnoreFiles` — resolving the clide-owned
+/// `ignore_files:` key from `.pql/config.yaml` (D-3 / D-4).
+library;
+
+import 'dart:io';
+
+import 'package:clide/src/files/pql_config.dart';
+import 'package:test/test.dart';
+
+void main() {
+  late Directory root;
+
+  setUp(() async {
+    root = await Directory.systemTemp.createTemp('clide-pqlconfig-');
+  });
+  tearDown(() async {
+    if (root.existsSync()) root.deleteSync(recursive: true);
+  });
+
+  void writeConfig(String body) {
+    Directory('${root.path}/.pql').createSync();
+    File('${root.path}/.pql/config.yaml').writeAsStringSync(body);
+  }
+
+  test('no config → defaults to [.gitignore]', () {
+    expect(readIgnoreFiles(root), ['.gitignore']);
+  });
+
+  test('no config but .clideignore present → adds it after .gitignore', () {
+    File('${root.path}/.clideignore').writeAsStringSync('build/\n');
+    expect(readIgnoreFiles(root), ['.gitignore', '.clideignore']);
+  });
+
+  test('explicit ignore_files list is honoured verbatim and in order', () {
+    writeConfig('ignore_files: [.gitignore, .pqlignore]\n');
+    expect(readIgnoreFiles(root), ['.gitignore', '.pqlignore']);
+  });
+
+  test('explicit empty list disables file-based exclusions', () {
+    writeConfig('ignore_files: []\n');
+    expect(readIgnoreFiles(root), isEmpty);
+  });
+
+  test('config present but key absent → default (ignores .clideignore rule only via default)', () {
+    writeConfig('frontmatter: yaml\n');
+    expect(readIgnoreFiles(root), ['.gitignore']);
+  });
+
+  test('non-string entries are dropped from the list', () {
+    writeConfig('ignore_files: [.gitignore, 42, .pqlignore]\n');
+    expect(readIgnoreFiles(root), ['.gitignore', '.pqlignore']);
+  });
+
+  test('malformed YAML falls back to the default (never throws)', () {
+    writeConfig('ignore_files: [unterminated\n:::bad');
+    expect(readIgnoreFiles(root), ['.gitignore']);
+  });
+
+  test('ignore_files set to a scalar (not a list) falls back to default', () {
+    writeConfig('ignore_files: .gitignore\n');
+    expect(readIgnoreFiles(root), ['.gitignore']);
+  });
+}

test/files/walk_test.dart

@@ -0,0 +1,65 @@
+/// Tests for `walkFiles` — the recursive, ignore-pruned, capped
+/// workspace file walk behind `files.walk` and the search engine.
+library;
+
+import 'dart:io';
+
+import 'package:clide/src/files/ignore.dart';
+import 'package:clide/src/files/listing.dart';
+import 'package:test/test.dart';
+
+void main() {
+  late Directory root;
+
+  setUp(() async {
+    root = await Directory.systemTemp.createTemp('clide-walk-');
+    File('${root.path}/README.md').writeAsStringSync('a');
+    File('${root.path}/pubspec.yaml').writeAsStringSync('b');
+    Directory('${root.path}/lib/src').createSync(recursive: true);
+    File('${root.path}/lib/main.dart').writeAsStringSync('c');
+    File('${root.path}/lib/src/util.dart').writeAsStringSync('d');
+    Directory('${root.path}/build').createSync();
+    File('${root.path}/build/output.bin').writeAsStringSync('e');
+  });
+  tearDown(() async {
+    if (root.existsSync()) root.deleteSync(recursive: true);
+  });
+
+  test('walks recursively, returns files sorted by path', () async {
+    final r = await walkFiles(root: root, ignore: IgnoreSet([]));
+    expect(r.truncated, isFalse);
+    expect(r.files.map((e) => e.path).toList(), [
+      'README.md',
+      'build/output.bin',
+      'lib/main.dart',
+      'lib/src/util.dart',
+      'pubspec.yaml',
+    ]);
+  });
+
+  test('prunes ignored directories (build/ via builtin ignore)', () async {
+    final r = await walkFiles(root: root, ignore: IgnoreSet.builtin());
+    final paths = r.files.map((e) => e.path).toList();
+    expect(paths, isNot(contains('build/output.bin')));
+    expect(paths, containsAll(['README.md', 'lib/main.dart', 'lib/src/util.dart']));
+  });
+
+  test('emits only files, never directory entries', () async {
+    final r = await walkFiles(root: root, ignore: IgnoreSet([]));
+    expect(r.files.every((e) => !e.isDirectory), isTrue);
+  });
+
+  test('respects the maxFiles cap and flags truncation', () async {
+    final r = await walkFiles(root: root, ignore: IgnoreSet([]), maxFiles: 2);
+    expect(r.truncated, isTrue);
+    expect(r.files, hasLength(2));
+  });
+
+  test('an empty workspace yields no files and is not truncated', () async {
+    final empty = await Directory.systemTemp.createTemp('clide-walk-empty-');
+    addTearDown(() => empty.deleteSync(recursive: true));
+    final r = await walkFiles(root: empty, ignore: IgnoreSet([]));
+    expect(r.files, isEmpty);
+    expect(r.truncated, isFalse);
+  });
+}