fix Flutter Web/Chrome compile by stubbing SQLCipher DB

dart:ffi and SQLCipher cannot compile for Chrome. Split AppDatabase into
native (Drift+SQLCipher) and web in-memory stub via conditional export, and
enable the web platform so flutter run -d chrome works for UI preview.

Co-authored-by: okuma <o0kuma@users.noreply.github.com>

mobile/.metadata

@@ -15,7 +15,7 @@ migration:
     - platform: root
       create_revision: d7b523b356d15fb81e7d340bbe52b47f93937323
       base_revision: d7b523b356d15fb81e7d340bbe52b47f93937323
-    - platform: android
+    - platform: web
       create_revision: d7b523b356d15fb81e7d340bbe52b47f93937323
       base_revision: d7b523b356d15fb81e7d340bbe52b47f93937323
 

mobile/lib/db/app_database.dart

@@ -1,128 +1,5 @@
-import 'dart:ffi';
-import 'dart:io';
-import 'dart:math';
-
-import 'package:drift/drift.dart';
-import 'package:drift/native.dart';
-import 'package:flutter/services.dart';
-import 'package:flutter_secure_storage/flutter_secure_storage.dart';
-import 'package:path/path.dart' as p;
-import 'package:path_provider/path_provider.dart';
-import 'package:sqlcipher_flutter_libs/sqlcipher_flutter_libs.dart';
-import 'package:sqlite3/open.dart';
-
-import 'tables.dart';
-
-part 'app_database.g.dart';
-
-@DriftDatabase(tables: [ToneSamples, LocalKv])
-class AppDatabase extends _$AppDatabase {
-  AppDatabase(super.e);
-
-  @override
-  int get schemaVersion => 1;
-
-  /// In-memory DB for unit tests (no SQLCipher / filesystem).
-  factory AppDatabase.memory() => AppDatabase(NativeDatabase.memory());
-
-  /// Production opener: encrypted on-device file (tech-design.md §8).
-  static Future<AppDatabase> open() async {
-    final db = AppDatabase(_openEncryptedExecutor());
-    // Force open so missing SQLCipher SO fails here (caller can fall back).
-    await db.customSelect('SELECT 1').get();
-    return db;
-  }
-
-  Future<List<String>> loadToneSamples() async {
-    final rows = await (select(toneSamples)..orderBy([(t) => OrderingTerm.asc(t.sortOrder)])).get();
-    return rows.map((r) => r.sampleText).toList();
-  }
-
-  Future<void> replaceToneSamples(List<String> samples) async {
-    final now = DateTime.now().millisecondsSinceEpoch;
-    await transaction(() async {
-      await delete(toneSamples).go();
-      for (var i = 0; i < samples.length; i++) {
-        await into(toneSamples).insert(
-          ToneSamplesCompanion.insert(
-            id: 'tone_${i}_$now',
-            sampleText: samples[i],
-            createdAtMs: now,
-            sortOrder: i,
-          ),
-        );
-      }
-    });
-  }
-
-  Future<String?> getKv(String key) async {
-    final row = await (select(localKv)..where((t) => t.key.equals(key))).getSingleOrNull();
-    return row?.value;
-  }
-
-  Future<void> setKv(String key, String value) async {
-    await into(localKv).insertOnConflictUpdate(LocalKvCompanion.insert(key: key, value: value));
-  }
-
-  Future<bool> getBoolKv(String key, {bool defaultValue = false}) async {
-    final v = await getKv(key);
-    if (v == null) return defaultValue;
-    return v == '1' || v.toLowerCase() == 'true';
-  }
-
-  Future<void> setBoolKv(String key, bool value) async {
-    await setKv(key, value ? '1' : '0');
-  }
-}
-
-const _kDbPassphrase = 'db_passphrase_v1';
-
-QueryExecutor _openEncryptedExecutor() {
-  return LazyDatabase(() async {
-    final dir = await getApplicationDocumentsDirectory();
-    final file = File(p.join(dir.path, 'bunsin_encrypted.db'));
-    final passphrase = await _loadOrCreatePassphrase();
-
-    // Background isolate does not inherit open.overrideFor — re-apply there.
-    final token = RootIsolateToken.instance;
-    return NativeDatabase.createInBackground(
-      file,
-      isolateSetup: () async {
-        if (token != null) {
-          BackgroundIsolateBinaryMessenger.ensureInitialized(token);
-        }
-        await _configureSqlCipherOpen();
-      },
-      setup: (rawDb) {
-        // SQLCipher key must be set before any other statement.
-        final escaped = passphrase.replaceAll("'", "''");
-        rawDb.execute("PRAGMA key = '$escaped'");
-        rawDb.config.doubleQuotedStringLiterals = false;
-      },
-    );
-  });
-}
-
-Future<void> _configureSqlCipherOpen() async {
-  if (Platform.isAndroid) {
-    await applyWorkaroundToOpenSqlCipherOnOldAndroidVersions();
-    open.overrideFor(OperatingSystem.android, openCipherOnAndroid);
-  } else if (Platform.isLinux) {
-    // Desktop/dev: try SQLCipher SO; fall back is handled by open() failure upstream.
-    open.overrideFor(OperatingSystem.linux, () => DynamicLibrary.open('libsqlcipher.so'));
-  } else if (Platform.isWindows) {
-    open.overrideFor(OperatingSystem.windows, () => DynamicLibrary.open('sqlcipher.dll'));
-  }
-  // iOS/macOS: sqlcipher_flutter_libs links into the process.
-}
-
-Future<String> _loadOrCreatePassphrase() async {
-  const storage = FlutterSecureStorage();
-  final existing = await storage.read(key: _kDbPassphrase);
-  if (existing != null && existing.isNotEmpty) return existing;
-  final rand = Random.secure();
-  final bytes = List<int>.generate(32, (_) => rand.nextInt(256));
-  final passphrase = bytes.map((b) => b.toRadixString(16).padLeft(2, '0')).join();
-  await storage.write(key: _kDbPassphrase, value: passphrase);
-  return passphrase;
-}
+/// Platform-specific local database entrypoint.
+///
+/// - IO (Android / iOS / Linux / …): Drift + SQLCipher (`app_database_native.dart`)
+/// - Web (Chrome): in-memory stub (`app_database_web.dart`) — FFI cannot compile
+export 'app_database_native.dart' if (dart.library.html) 'app_database_web.dart';

mobile/lib/db/app_database.g.dart

@@ -1,6 +1,6 @@
 // GENERATED CODE - DO NOT MODIFY BY HAND
 
-part of 'app_database.dart';
+part of 'app_database_native.dart';
 
 // ignore_for_file: type=lint
 class $ToneSamplesTable extends ToneSamples

mobile/lib/db/app_database_native.dart

@@ -0,0 +1,131 @@
+import 'dart:ffi';
+import 'dart:io';
+import 'dart:math';
+
+import 'package:drift/drift.dart';
+import 'package:drift/native.dart';
+import 'package:flutter/services.dart';
+import 'package:flutter_secure_storage/flutter_secure_storage.dart';
+import 'package:path/path.dart' as p;
+import 'package:path_provider/path_provider.dart';
+import 'package:sqlcipher_flutter_libs/sqlcipher_flutter_libs.dart';
+import 'package:sqlite3/open.dart';
+
+import 'tables.dart';
+
+part 'app_database.g.dart';
+
+@DriftDatabase(tables: [ToneSamples, LocalKv])
+class AppDatabase extends _$AppDatabase {
+  AppDatabase(super.e, {this.encrypted = false});
+
+  /// True when backed by on-device SQLCipher (not memory / web stub).
+  final bool encrypted;
+
+  @override
+  int get schemaVersion => 1;
+
+  /// In-memory DB for unit tests (no SQLCipher / filesystem).
+  factory AppDatabase.memory() => AppDatabase(NativeDatabase.memory(), encrypted: false);
+
+  /// Production opener: encrypted on-device file (tech-design.md §8).
+  static Future<AppDatabase> open() async {
+    final db = AppDatabase(_openEncryptedExecutor(), encrypted: true);
+    // Force open so missing SQLCipher SO fails here (caller can fall back).
+    await db.customSelect('SELECT 1').get();
+    return db;
+  }
+
+  Future<List<String>> loadToneSamples() async {
+    final rows = await (select(toneSamples)..orderBy([(t) => OrderingTerm.asc(t.sortOrder)])).get();
+    return rows.map((r) => r.sampleText).toList();
+  }
+
+  Future<void> replaceToneSamples(List<String> samples) async {
+    final now = DateTime.now().millisecondsSinceEpoch;
+    await transaction(() async {
+      await delete(toneSamples).go();
+      for (var i = 0; i < samples.length; i++) {
+        await into(toneSamples).insert(
+          ToneSamplesCompanion.insert(
+            id: 'tone_${i}_$now',
+            sampleText: samples[i],
+            createdAtMs: now,
+            sortOrder: i,
+          ),
+        );
+      }
+    });
+  }
+
+  Future<String?> getKv(String key) async {
+    final row = await (select(localKv)..where((t) => t.key.equals(key))).getSingleOrNull();
+    return row?.value;
+  }
+
+  Future<void> setKv(String key, String value) async {
+    await into(localKv).insertOnConflictUpdate(LocalKvCompanion.insert(key: key, value: value));
+  }
+
+  Future<bool> getBoolKv(String key, {bool defaultValue = false}) async {
+    final v = await getKv(key);
+    if (v == null) return defaultValue;
+    return v == '1' || v.toLowerCase() == 'true';
+  }
+
+  Future<void> setBoolKv(String key, bool value) async {
+    await setKv(key, value ? '1' : '0');
+  }
+}
+
+const _kDbPassphrase = 'db_passphrase_v1';
+
+QueryExecutor _openEncryptedExecutor() {
+  return LazyDatabase(() async {
+    final dir = await getApplicationDocumentsDirectory();
+    final file = File(p.join(dir.path, 'bunsin_encrypted.db'));
+    final passphrase = await _loadOrCreatePassphrase();
+
+    // Background isolate does not inherit open.overrideFor — re-apply there.
+    final token = RootIsolateToken.instance;
+    return NativeDatabase.createInBackground(
+      file,
+      isolateSetup: () async {
+        if (token != null) {
+          BackgroundIsolateBinaryMessenger.ensureInitialized(token);
+        }
+        await _configureSqlCipherOpen();
+      },
+      setup: (rawDb) {
+        // SQLCipher key must be set before any other statement.
+        final escaped = passphrase.replaceAll("'", "''");
+        rawDb.execute("PRAGMA key = '$escaped'");
+        rawDb.config.doubleQuotedStringLiterals = false;
+      },
+    );
+  });
+}
+
+Future<void> _configureSqlCipherOpen() async {
+  if (Platform.isAndroid) {
+    await applyWorkaroundToOpenSqlCipherOnOldAndroidVersions();
+    open.overrideFor(OperatingSystem.android, openCipherOnAndroid);
+  } else if (Platform.isLinux) {
+    // Desktop/dev: try SQLCipher SO; fall back is handled by open() failure upstream.
+    open.overrideFor(OperatingSystem.linux, () => DynamicLibrary.open('libsqlcipher.so'));
+  } else if (Platform.isWindows) {
+    open.overrideFor(OperatingSystem.windows, () => DynamicLibrary.open('sqlcipher.dll'));
+  }
+  // iOS/macOS: sqlcipher_flutter_libs links into the process.
+}
+
+Future<String> _loadOrCreatePassphrase() async {
+  const storage = FlutterSecureStorage();
+  final existing = await storage.read(key: _kDbPassphrase);
+  if (existing != null && existing.isNotEmpty) return existing;
+  final rand = Random.secure();
+  final bytes = List<int>.generate(32, (_) => rand.nextInt(256));
+  final passphrase = bytes.map((b) => b.toRadixString(16).padLeft(2, '0')).join();
+  await storage.write(key: _kDbPassphrase, value: passphrase);
+  return passphrase;
+}

mobile/lib/db/app_database_web.dart

@@ -0,0 +1,42 @@
+/// Web/Chrome stub for [AppDatabase].
+///
+/// SQLCipher / dart:ffi cannot compile for Flutter Web. Chrome runs use an
+/// in-tab memory map so UI + API flows still work. Persistence is not encrypted
+/// and is lost on refresh (web is a preview surface, not the release target).
+class AppDatabase {
+  AppDatabase({this.encrypted = false});
+
+  /// Always false on web — there is no SQLCipher path.
+  final bool encrypted;
+
+  final Map<String, String> _kv = {};
+  List<String> _toneSamples = [];
+
+  factory AppDatabase.memory() => AppDatabase(encrypted: false);
+
+  static Future<AppDatabase> open() async => AppDatabase(encrypted: false);
+
+  Future<List<String>> loadToneSamples() async => List<String>.from(_toneSamples);
+
+  Future<void> replaceToneSamples(List<String> samples) async {
+    _toneSamples = List<String>.from(samples);
+  }
+
+  Future<String?> getKv(String key) async => _kv[key];
+
+  Future<void> setKv(String key, String value) async {
+    _kv[key] = value;
+  }
+
+  Future<bool> getBoolKv(String key, {bool defaultValue = false}) async {
+    final v = await getKv(key);
+    if (v == null) return defaultValue;
+    return v == '1' || v.toLowerCase() == 'true';
+  }
+
+  Future<void> setBoolKv(String key, bool value) async {
+    await setKv(key, value ? '1' : '0');
+  }
+
+  Future<void> close() async {}
+}

mobile/lib/screens/data_flow_screen.dart

@@ -32,7 +32,9 @@ class DataFlowScreen extends StatelessWidget {
               subtitle: Text(
                 [
                   samples.isEmpty ? '(아직 없음 — 말투 샘플 화면에서 추가)' : samples.take(3).join(' · '),
-                  session.localDbEncrypted ? '저장: drift + SQLCipher(암호화)' : '저장: 메모리 폴백(이 환경에 SQLCipher 없음)',
+                  session.localDbEncrypted
+                      ? '저장: drift + SQLCipher(암호화)'
+                      : '저장: 메모리/웹 스텁(이 환경에 SQLCipher 없음 — Chrome·Linux 폴백)',
                 ].join('\n'),
               ),
               isThreeLine: true,

mobile/lib/state/session_state.dart

@@ -60,11 +60,12 @@ class SessionState extends ChangeNotifier {
   Future<AppDatabase> _openDb() async {
     try {
       final db = await AppDatabase.open();
-      localDbEncrypted = true;
+      localDbEncrypted = db.encrypted;
       return db;
     } catch (e) {
       // Linux CI / hosts without libsqlcipher.so — fall back to memory so the
       // app still boots; Android release path uses SQLCipher.
+      // Web uses an in-memory stub via conditional import (no FFI).
       debugPrint('Encrypted DB unavailable ($e); using in-memory fallback');
       localDbEncrypted = false;
       return AppDatabase.memory();

mobile/web/index.html

@@ -0,0 +1,38 @@
+<!DOCTYPE html>
+<html>
+<head>
+  <!--
+    If you are serving your web app in a path other than the root, change the
+    href value below to reflect the base path you are serving from.
+
+    The path provided below has to start and end with a slash "/" in order for
+    it to work correctly.
+
+    For more details:
+    * https://developer.mozilla.org/en-US/docs/Web/HTML/Element/base
+
+    This is a placeholder for base href that will be replaced by the value of
+    the `--base-href` argument provided to `flutter build`.
+  -->
+  <base href="$FLUTTER_BASE_HREF">
+
+  <meta charset="UTF-8">
+  <meta content="IE=Edge" http-equiv="X-UA-Compatible">
+  <meta name="description" content="A new Flutter project.">
+
+  <!-- iOS meta tags & icons -->
+  <meta name="mobile-web-app-capable" content="yes">
+  <meta name="apple-mobile-web-app-status-bar-style" content="black">
+  <meta name="apple-mobile-web-app-title" content="bunsin_mobile">
+  <link rel="apple-touch-icon" href="icons/Icon-192.png">
+
+  <!-- Favicon -->
+  <link rel="icon" type="image/png" href="favicon.png"/>
+
+  <title>bunsin_mobile</title>
+  <link rel="manifest" href="manifest.json">
+</head>
+<body>
+  <script src="flutter_bootstrap.js" async></script>
+</body>
+</html>

mobile/web/manifest.json

@@ -0,0 +1,35 @@
+{
+    "name": "bunsin_mobile",
+    "short_name": "bunsin_mobile",
+    "start_url": ".",
+    "display": "standalone",
+    "background_color": "#0175C2",
+    "theme_color": "#0175C2",
+    "description": "A new Flutter project.",
+    "orientation": "portrait-primary",
+    "prefer_related_applications": false,
+    "icons": [
+        {
+            "src": "icons/Icon-192.png",
+            "sizes": "192x192",
+            "type": "image/png"
+        },
+        {
+            "src": "icons/Icon-512.png",
+            "sizes": "512x512",
+            "type": "image/png"
+        },
+        {
+            "src": "icons/Icon-maskable-192.png",
+            "sizes": "192x192",
+            "type": "image/png",
+            "purpose": "maskable"
+        },
+        {
+            "src": "icons/Icon-maskable-512.png",
+            "sizes": "512x512",
+            "type": "image/png",
+            "purpose": "maskable"
+        }
+    ]
+}