fix(claude): 修复工具调用兼容与解析回退

- Claude 工具定义兼容 input_schema 与 function.parameters

- tool_calls 解析增加 thinking 回退与大小写无关工具名匹配

- 补充 claude/util 相关回归测试

internal/format/claude/render.go

@@ -9,6 +9,9 @@ import (
 
 func BuildMessageResponse(messageID, model string, normalizedMessages []any, finalThinking, finalText string, toolNames []string) map[string]any {
 	detected := util.ParseToolCalls(finalText, toolNames)
+	if len(detected) == 0 && finalThinking != "" {
+		detected = util.ParseToolCalls(finalThinking, toolNames)
+	}
 	content := make([]map[string]any, 0, 4)
 	if finalThinking != "" {
 		content = append(content, map[string]any{"type": "thinking", "thinking": finalThinking})

internal/format/claude/render_test.go

@@ -0,0 +1,29 @@
+package claude
+
+import "testing"
+
+func TestBuildMessageResponseDetectsToolCallsFromThinkingFallback(t *testing.T) {
+	resp := BuildMessageResponse(
+		"msg_1",
+		"claude-sonnet-4-5",
+		[]any{map[string]any{"role": "user", "content": "hi"}},
+		`{"tool_calls":[{"name":"search","input":{"q":"go"}}]}`,
+		"",
+		[]string{"search"},
+	)
+
+	if resp["stop_reason"] != "tool_use" {
+		t.Fatalf("expected stop_reason=tool_use, got=%#v", resp["stop_reason"])
+	}
+	content, _ := resp["content"].([]map[string]any)
+	if len(content) < 2 {
+		t.Fatalf("expected thinking + tool_use content blocks, got=%#v", resp["content"])
+	}
+	last := content[len(content)-1]
+	if last["type"] != "tool_use" {
+		t.Fatalf("expected last content block tool_use, got=%#v", last["type"])
+	}
+	if last["name"] != "search" {
+		t.Fatalf("expected tool name search, got=%#v", last["name"])
+	}
+}