feat(bedrock): add Claude Code compatibility transformations for Bedrock accounts

Add channel-level Bedrock CC compatibility toggle (similar to web_search_emulation)
that fixes 4 types of Bedrock 400 errors seen with Claude Code:

1. thinking.type "enabled" → "adaptive" for Opus 4.7+ (only supports adaptive)
2. Add default budget_tokens when missing for older models
3. Replace illegal characters in tool_use IDs to match Bedrock's ^[a-zA-Z0-9_-]+$ pattern
4. anthropic_version / invalid beta flag (already handled elsewhere)

Transformations run in Forward() before any forwarding path, so both native Bedrock
accounts and apikey passthrough accounts pointing to Bedrock relays benefit.

Includes channel-level toggle UI and unit tests.

frontend/src/i18n/locales/en.ts

@@ -2358,6 +2358,8 @@ export default {
         webSearchEmulationGlobalDisabled: 'Please enable the global switch first in Settings → Gateway → Web Search Emulation',
         codexImageGenerationBridge: 'Codex Image Generation Bridge',
         codexImageGenerationBridgeHint: 'When enabled, Codex /responses text requests in OpenAI groups may be automatically given the image_generation tool. Keep off unless the routed accounts support image generation.',
+        bedrockCCCompat: 'Bedrock CC Compatibility',
+        bedrockCCCompatHint: '⚠️ When enabled, requests to Bedrock accounts in this channel will be transformed for Claude Code compatibility (thinking type conversion, tool_use ID sanitization).',
         basicSettings: 'Basic Settings',
         addPlatform: 'Add Platform',
         noPlatforms: 'Click "Add Platform" to start configuring the channel',

frontend/src/i18n/locales/zh.ts

@@ -2435,6 +2435,8 @@ export default {
         webSearchEmulationGlobalDisabled: '请先在系统设置 → 网关 → Web Search 模拟中启用全局开关',
         codexImageGenerationBridge: 'Codex 图片生成桥接',
         codexImageGenerationBridgeHint: '开启后，OpenAI 分组的 Codex /responses 文本请求可能会被自动注入 image_generation 工具。仅在路由账号支持图片生成时开启。',
+        bedrockCCCompat: 'Bedrock CC 兼容',
+        bedrockCCCompatHint: '⚠️ 开启后，该渠道下 Bedrock 账号的请求将进行 Claude Code 兼容处理（thinking 类型转换、tool_use ID 清理）',
         basicSettings: '基础设置',
         addPlatform: '添加平台',
         noPlatforms: '点击"添加平台"开始配置渠道',