feat(api): 统一 LLM JSON 调用层 llm_json_call，按域 Schema 迁移 chat/memoir agents

api/app/agents/memoir/classification_agent.py

@@ -14,13 +14,15 @@ from dataclasses import dataclass
 from typing import Any
 
 from app.agents.memoir.prompts import get_chapter_classification_json_prompt
+from app.agents.memoir.schemas import ClassificationOutput
 from app.agents.stage_constants import (
     CHAPTER_CATEGORIES,
     STAGE_KEYWORD_WEIGHTS,
     STAGE_TO_DEFAULT_CATEGORY,
 )
+from app.core.config import settings
 from app.core.json_utils import extract_json_payload
-from app.core.langchain_llm import invoke_json_object
+from app.core.llm_call import llm_json_call
 from app.core.logging import get_logger
 
 logger = get_logger(__name__)
@@ -135,13 +137,14 @@ class ClassificationAgent:
         if llm:
             try:
                 prompt = get_chapter_classification_json_prompt(text)
-                raw = invoke_json_object(
+                out = llm_json_call(
                     llm,
                     prompt,
-                    max_tokens=256,
+                    ClassificationOutput,
+                    max_tokens=settings.memoir_classification_max_tokens,
                     agent="ClassificationAgent.classify",
                 )
-                category = _parse_category_from_llm_response(raw)
+                category = _normalize_llm_category(out.category)
                 if category == "none":
                     logger.info(
                         "event=chapter_classification_summary_fallback reason=llm_none "