feat: Add comprehensive Amazon Bedrock integration support

Add complete Amazon Bedrock integration to Claude Relay Service with:

## Core Features
- ✅ Bedrock account management with encrypted AWS credential storage
- ✅ Full request routing to AWS Bedrock with streaming support
- ✅ Integration with unified Claude scheduler system
- ✅ Support for Inference Profiles and Application Inference Profiles
- ✅ Configurable default and small-fast model settings

## Backend Services
- Add bedrockAccountService.js for account management
- Add bedrockRelayService.js for request forwarding
- Integrate Bedrock accounts into unifiedClaudeScheduler.js
- Update admin and API routes to support Bedrock endpoints
- Add comprehensive configuration options to config.example.js

## Frontend Integration
- Complete Vue.js Web UI for Bedrock account management
- Account creation form with AWS credentials and model configuration
- Real-time account status monitoring and statistics
- Edit/update capabilities for existing accounts

## CLI Support
- Interactive CLI commands for Bedrock account operations
- Account creation, listing, updating, and testing
- Status monitoring and connection validation

## Security & Performance
- AES encrypted storage of AWS credentials in Redis
- Support for temporary credentials (session tokens)
- Region-specific configuration support
- Rate limiting and error handling

This integration enables the relay service to support three AI platforms:
1. Claude (OAuth) - Original Claude.ai integration
2. Gemini - Google AI integration
3. Amazon Bedrock - New AWS Bedrock integration

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

config/config.example.js

@@ -39,6 +39,18 @@ const config = {
     betaHeader: process.env.CLAUDE_BETA_HEADER || 'claude-code-20250219,oauth-2025-04-20,interleaved-thinking-2025-05-14,fine-grained-tool-streaming-2025-05-14'
   },
 
+  // ☁️ Bedrock API配置
+  bedrock: {
+    enabled: process.env.CLAUDE_CODE_USE_BEDROCK === '1',
+    defaultRegion: process.env.AWS_REGION || 'us-east-1',
+    smallFastModelRegion: process.env.ANTHROPIC_SMALL_FAST_MODEL_AWS_REGION,
+    defaultModel: process.env.ANTHROPIC_MODEL || 'us.anthropic.claude-3-7-sonnet-20250219-v1:0',
+    smallFastModel: process.env.ANTHROPIC_SMALL_FAST_MODEL || 'us.anthropic.claude-3-5-haiku-20241022-v1:0',
+    maxOutputTokens: parseInt(process.env.CLAUDE_CODE_MAX_OUTPUT_TOKENS) || 4096,
+    maxThinkingTokens: parseInt(process.env.MAX_THINKING_TOKENS) || 1024,
+    enablePromptCaching: process.env.DISABLE_PROMPT_CACHING !== '1'
+  },
+
   // 🌐 代理配置
   proxy: {
     timeout: parseInt(process.env.DEFAULT_PROXY_TIMEOUT) || 30000,