fix(openclaw): robust JSON repair for small LLM responses

apps/api/src/services/openclaw.py

@@ -942,31 +942,61 @@ class OpenClawService:
     # =========================================================================
 
     def _extract_json_from_response(self, text: str) -> str | None:
-        """從 LLM 回應中提取 JSON"""
-        # 嘗試直接解析
+        """從 LLM 回應中提取 JSON (含啟發式修補)"""
+        # 0. 清理開頭結尾空白
+        text = text.strip()
+        if not text:
+            return None
+
+        # 1. 嘗試直接解析
         try:
             json.loads(text)
             return text
         except json.JSONDecodeError:
             pass
 
-        # 嘗試從 markdown code block 提取
+        # 2. 嘗試從 markdown code block 提取
         patterns = [
             r"```json\s*([\s\S]*?)\s*```",
             r"```\s*([\s\S]*?)\s*```",
-            r"\{[\s\S]*\}",
+            r"(\{[\s\S]*\})", # 貪婪匹配最大括號對
         ]
 
         for pattern in patterns:
             match = re.search(pattern, text)
             if match:
-                candidate = match.group(1) if "```" in pattern else match.group(0)
+                candidate = match.group(1) if "(" in pattern else match.group(0)
+                candidate = candidate.strip()
                 try:
                     json.loads(candidate)
                     return candidate
                 except json.JSONDecodeError:
+                    # 3. 啟發式修補: 如果結尾缺少括號，嘗試補齊
+                    if candidate.startswith("{") and not candidate.endswith("}"):
+                        for i in range(1, 5): # 嘗試補 1-5 個括號/引號
+                             try:
+                                 repaired = candidate + '"' * (i-1) + "}" * i
+                                 json.loads(repaired)
+                                 logger.info("json_repaired_heuristically", level=i)
+                                 return repaired
+                             except:
+                                 continue
                     continue
 
+        # 4. 極端情況: 找出最後一個有效 key
+        if "{" in text:
+            start_idx = text.find("{")
+            candidate = text[start_idx:]
+            # 暴力去除非法尾綴 (如 \t\t...)
+            candidate = re.sub(r"[ \t\r\n]+$", "", candidate)
+            if not candidate.endswith("}"):
+                candidate += '"}' # 嘗試最簡單的閉合
+            try:
+                json.loads(candidate)
+                return candidate
+            except:
+                pass
+
         return None
 
     def _parse_analysis_result(self, raw_response: str) -> OpenClawDecision | None: