refactor(client): Phase 0.1 统一中文字体地基（golden 消豆腐块，可与原型保真比对）

- 打包 Noto Sans SC（pubspec fonts:），ThemeData.fontFamily 全平台统一
- golden_harness 用 FontLoader 注入 ttf + withGoldenFont，golden 渲染真实中文
- 修复 data_table_card 根因：DefaultTextStyle → .merge（替换式会吞掉继承字体，
  导致所有表格屏表头/单元格渲染豆腐块）；顺手 hover 硬编码色 → context.tokens.rowHover
- 全部 golden 用新字体重生成；test/golden/failures/ 加入 gitignore

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01TSKEiHsvauyxYUW2itzUXX

client/.gitignore

@@ -33,6 +33,9 @@ migrate_working_dir/
 /build/
 /coverage/
 
+# Golden test diff artifacts (transient, regenerated on failure)
+test/golden/failures/
+
 # Symbolication related
 app.*.symbols
 

client/lib/core/theme/themes.dart

@@ -18,7 +18,8 @@ ThemeData buildTheme(String key) {
     brightness: brightness,
     colorScheme: scheme,
     scaffoldBackgroundColor: t.bg,
-    fontFamily: null, // 系统中文字体；字号梯度后续在组件层接入
+    // 全平台统一中文字体（与原型截图、golden 保真 diff 一致）；打包内置。
+    fontFamily: 'NotoSansSC',
     extensions: <ThemeExtension<dynamic>>[t],
   );
 }

client/lib/widgets/data_table_card.dart

@@ -156,7 +156,7 @@ class _DataTableCardState extends State<DataTableCard> {
       children: widget.columns.map((col) {
         return Padding(
           padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 12),
-          child: DefaultTextStyle(
+          child: DefaultTextStyle.merge(
             style: TextStyle(
               fontSize: 13,
               fontWeight: FontWeight.w600,
@@ -187,10 +187,10 @@ class _DataTableCardState extends State<DataTableCard> {
               constraints: const BoxConstraints(minHeight: 48),
               alignment:
                   col.numeric ? Alignment.centerRight : Alignment.centerLeft,
-              color: hovered == rowIndex ? const Color(0xFFF5F7FF) : null,
+              color: hovered == rowIndex ? context.tokens.rowHover : null,
               padding:
                   const EdgeInsets.symmetric(horizontal: 16, vertical: 10),
-              child: DefaultTextStyle(
+              child: DefaultTextStyle.merge(
                 style: TextStyle(
                     fontSize: 13, color: context.tokens.text),
                 child: cell.child,

client/pubspec.yaml

@@ -62,5 +62,11 @@ flutter:
 
   assets:
     - assets/fonts/NotoSansSC-Regular.ttf
+    - assets/fonts/NotoSansSC.ttf
     - assets/config/app_info.json
     - assets/brand/logo_mark.png
+
+  fonts:
+    - family: NotoSansSC
+      fonts:
+        - asset: assets/fonts/NotoSansSC.ttf

client/test/support/golden_harness.dart

@@ -1,8 +1,26 @@
 import 'package:flutter/material.dart';
+import 'package:flutter/services.dart' show rootBundle, FontLoader;
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:jiu_client/core/theme/themes.dart';
 
+// 加载真实中文字体（消除 golden 豆腐块），使 golden 能与原型截图做保真 diff。
+// 原型截图侧同样注入 Noto Sans SC（见 tools/fidelity.mjs），两边字体一致。
+bool _fontsLoaded = false;
+Future<void> ensureGoldenFonts() async {
+  if (_fontsLoaded) return;
+  final loader = FontLoader('NotoSansSC')
+    ..addFont(rootBundle.load('assets/fonts/NotoSansSC.ttf'));
+  await loader.load();
+  _fontsLoaded = true;
+}
+
+/// 把 NotoSansSC 套到主题文字上（含 hardcoded TextStyle 经 DefaultTextStyle 继承）。
+ThemeData withGoldenFont(ThemeData base) => base.copyWith(
+      textTheme: base.textTheme.apply(fontFamily: 'NotoSansSC'),
+      primaryTextTheme: base.primaryTextTheme.apply(fontFamily: 'NotoSansSC'),
+    );
+
 /// design-distill 阶段4（Flutter 端）可复用 golden 骨架。
 /// 在指定主题 / viewport 下渲染 [child]（含 provider 覆盖），比对/更新 golden。
 ///
@@ -23,6 +41,7 @@ Future<void> pumpGolden(
   Size logical = const Size(1280, 900),
   double dpr = 2.0,
 }) async {
+  await ensureGoldenFonts();
   tester.view.physicalSize = Size(logical.width * dpr, logical.height * dpr);
   tester.view.devicePixelRatio = dpr;
   addTearDown(tester.view.resetPhysicalSize);
@@ -32,7 +51,7 @@ Future<void> pumpGolden(
     overrides: overrides,
     child: MaterialApp(
       debugShowCheckedModeBanner: false,
-      theme: buildTheme(theme),
+      theme: withGoldenFont(buildTheme(theme)),
       home: child,
     ),
   ));