docs(theme): update documentation and clean up deprecated color scheme definitions

Removed outdated compatibility aliases and deprecated methods from AppColorScheme,
and updated CLAUDE.md to reflect new theme system requirements with centralized
color management and no hard-coded values in UI components.

flutter_monisuo/lib/ui/pages/trade/components/amount_input.dart

@@ -1,7 +1,7 @@
 import 'package:flutter/material.dart';
-import 'package:google_fonts/google_fonts.dart';
 import '../../../../core/theme/app_color_scheme.dart';
 import '../../../../core/theme/app_spacing.dart';
+import '../../../../core/theme/app_theme.dart';
 
 /// 金额输入框组件（含超额提示）
 ///
@@ -70,17 +70,13 @@ class _AmountInputState extends State<AmountInput> {
             controller: widget.amountController,
             keyboardType: const TextInputType.numberWithOptions(decimal: true),
             onChanged: (_) => _checkLimit(),
-            style: GoogleFonts.inter(
-              fontSize: 14,
-              fontWeight: FontWeight.normal,
-              color: colorScheme.onSurface,
-              fontFeatures: [FontFeature.tabularFigures()],
+            style: AppTextStyles.numberMedium(context).copyWith(
+              fontWeight: FontWeight.w400,
             ),
             decoration: InputDecoration(
               hintText: '请输入金额',
-              hintStyle: GoogleFonts.inter(
-                fontSize: 14,
-                fontWeight: FontWeight.normal,
+              hintStyle: AppTextStyles.numberMedium(context).copyWith(
+                fontWeight: FontWeight.w400,
                 color: colorScheme.onSurfaceVariant.withOpacity(0.5),
               ),
               border: InputBorder.none,
@@ -96,11 +92,10 @@ class _AmountInputState extends State<AmountInput> {
             child: Row(
               children: [
                 Icon(Icons.error_outline, size: 13, color: warningColor),
-                SizedBox(width: 4),
+                SizedBox(width: AppSpacing.xs),
                 Text(
                   '超出可用USDT余额',
-                  style: GoogleFonts.inter(
-                    fontSize: 11,
+                  style: AppTextStyles.bodySmall(context).copyWith(
                     color: warningColor,
                   ),
                 ),