fix: add claude-opus-4-6 mapping and strip [1m] suffix for Bedrock

- Add model mapping: claude-opus-4-6 → us.anthropic.claude-opus-4-6-v1
- Strip [1m] suffix before model lookup (Claude Code sends e.g.
  claude-opus-4-6[1m] for 1M context variant)
- Bedrock supports 1M context natively for Opus 4.6, so the same
  model ID works — the [1m] suffix just needs to be removed

src/services/bedrockRelayService.js

@@ -433,8 +433,15 @@ class BedrockRelayService {
 
   // 将标准Claude模型名映射为Bedrock格式
   _mapToBedrockModel(modelName) {
+    // Strip [1m] suffix (long context variant) — Bedrock uses the same model ID
+    // but supports 1M context natively for models that have it
+    const cleanModelName = modelName.replace(/\[1m\]$/, '')
+
     // 标准Claude模型名到Bedrock模型名的映射表
     const modelMapping = {
+      // Claude Opus 4.6
+      'claude-opus-4-6': 'us.anthropic.claude-opus-4-6-v1',
+
       // Claude 4.5 Opus
       'claude-opus-4-5': 'us.anthropic.claude-opus-4-5-20251101-v1:0',
       'claude-opus-4-5-20251101': 'us.anthropic.claude-opus-4-5-20251101-v1:0',
@@ -479,21 +486,21 @@ class BedrockRelayService {
 
     // 如果已经是Bedrock格式，直接返回
     // Bedrock模型格式：{region}.anthropic.{model-name} 或 anthropic.{model-name}
-    if (modelName.includes('.anthropic.') || modelName.startsWith('anthropic.')) {
-      return modelName
+    if (cleanModelName.includes('.anthropic.') || cleanModelName.startsWith('anthropic.')) {
+      return cleanModelName
     }
 
     // 查找映射
-    const mappedModel = modelMapping[modelName]
+    const mappedModel = modelMapping[cleanModelName]
     if (mappedModel) {
       return mappedModel
     }
 
     // 如果没有找到映射，返回原始模型名（可能会导致错误，但保持向后兼容）
-    logger.warn(`⚠️ 未找到模型映射: ${modelName}，使用原始模型名`, {
+    logger.warn(`⚠️ 未找到模型映射: ${cleanModelName}，使用原始模型名`, {
       metadata: { originalModel: modelName }
     })
-    return modelName
+    return cleanModelName
   }
 
   // 选择使用的区域