fix: convert thinking.type=enabled to adaptive for Opus 4.7 in ClaudeHelper

Claude Code sends Anthropic format requests directly to /v1/messages with
thinking.type=enabled. ClaudeHelper was forwarding this unchanged to
upstream, but Opus 4.7 rejects thinking.type=enabled and requires
thinking.type=adaptive with output_config.effort instead.

heicode/relay/claude_handler.go

@@ -103,6 +103,25 @@ func ClaudeHelper(c *gin.Context, info *relaycommon.RelayInfo) (newAPIError *typ
 		info.UpstreamModelName = request.Model
 	}
 
+	// Opus 4.7 rejects thinking.type="enabled"; convert to adaptive.
+	if strings.HasPrefix(request.Model, "claude-opus-4-7") && request.Thinking != nil && request.Thinking.Type == "enabled" {
+		budgetTokens := 0
+		if request.Thinking.BudgetTokens != nil {
+			budgetTokens = *request.Thinking.BudgetTokens
+		}
+		effortLevel := "high"
+		if budgetTokens > 0 && budgetTokens <= 1024 {
+			effortLevel = "low"
+		} else if budgetTokens > 0 && budgetTokens <= 8192 {
+			effortLevel = "medium"
+		}
+		request.Thinking = &dto.Thinking{Type: "adaptive", Display: "summarized"}
+		request.OutputConfig = json.RawMessage(fmt.Sprintf(`{"effort":"%s"}`, effortLevel))
+		request.Temperature = nil
+		request.TopP = nil
+		request.TopK = nil
+	}
+
 	if info.ChannelSetting.SystemPrompt != "" {
 		if request.System == nil {
 			request.SetStringSystem(info.ChannelSetting.SystemPrompt)