feat: 添加结构化日志系统，更新LLM配置与全部文档

新增:
- backend/logger.py — 集中日志模块 (JSON格式 + trace_id + 独立llm.log)
- @log_node / @_log_route 装饰器覆盖17个节点和8个路由

改进:
- backend/llm.py — _LLMLoggingWrapper 自动记录LLM输入输出
- backend/llm.py — API Key优先读ANTHROPIC_API_KEY，模型名改为MiniMax-M2.7
- backend/llm.py — get_llm() 新增caller参数标识调用来源
- backend/validation.py — 新增验证结果/连接失败日志
- backend/session.py — 新增会话创建/删除日志
- app.py — 新增用户交互日志 (输入/执行/异常/会话操作)
- app.py — 提前导入torchvision抑制transformers懒加载报错
- .env.example — 新增LOG_DIR/LOG_LEVEL/ANTHROPIC_API_KEY等配置项
- .gitignore — 新增logs/和db/忽略规则

文档:
- ROADMAP.md — 新增阶段四: 可观测性
- README.md — 补充日志架构/LLM配置/项目结构
- CLAUDE.md — 同步最新配置/日志/MAX_RETRY(3)
- CODE_GUIDE.md — 新增第15章日志系统，更新架构图/LLM/配置

app.py

@@ -9,6 +9,15 @@
 
 import os
 import sys
+
+os.environ.setdefault("TRANSFORMERS_VERBOSITY", "error")
+
+try:
+    import torchvision
+except Exception:
+    pass
+
+import time
 from pathlib import Path
 
 import streamlit as st
@@ -23,6 +32,9 @@ from backend.session import (
     delete_session,
     list_all_sessions,
 )
+from backend.logger import get_logger, set_trace_id, generate_trace_id
+
+_app_log = get_logger("app")
 
 st.set_page_config(
     page_title="JRXML 代理",
@@ -32,7 +44,7 @@ st.set_page_config(
 )
 
 # 阻止 Streamlit 裸 'c' 键清除缓存，保留 Ctrl+C 复制行为
-st.components.v1.html("""
+st.html("""
 <script>
 (function() {
     const parent = window.parent.document;
@@ -48,7 +60,7 @@ st.components.v1.html("""
     }, true);
 })();
 </script>
-""", height=0)
+""")
 
 # ---- 节点名称 → 中文标签 ----
 NODE_LABELS = {
@@ -130,7 +142,22 @@ current_session_id = st.session_state.agent_state.get("session_id", "")
 
 def run_agent(user_input: str):
     """运行代理图：流式渲染节点进度 + LLM 文本。"""
+    trace_id = generate_trace_id()
+    set_trace_id(trace_id)
     agent_state = st.session_state.agent_state
+    session_id = agent_state.get("session_id", "")
+
+    _app_log.info(
+        "代理执行开始",
+        extra={
+            "session_id": session_id,
+            "trace_id": trace_id,
+            "user_input_preview": user_input[:200],
+            "user_input_length": len(user_input),
+            "has_jrxml": bool(agent_state.get("current_jrxml", "").strip()),
+            "intent": agent_state.get("intent", ""),
+        },
+    )
 
     if agent_state.get("current_jrxml") and agent_state.get("status") == "pass":
         agent_state["user_modification_request"] = user_input
@@ -222,6 +249,10 @@ def run_agent(user_input: str):
 
     except Exception as e:
         progress_placeholder.empty()
+        _app_log.error(
+            f"代理执行异常: {e}",
+            extra={"session_id": session_id, "error": str(e)},
+        )
         st.error(f"工作流异常: {e}")
         return
 
@@ -296,6 +327,17 @@ def run_agent(user_input: str):
     else:
         st.error("未产生结果，请重试。")
 
+    _app_log.info(
+        "代理执行完成",
+        extra={
+            "session_id": session_id,
+            "intent": final_state.get("intent", ""),
+            "status": final_state.get("status", ""),
+            "jrxml_length": len(final_state.get("current_jrxml", "")),
+            "retry_count": final_state.get("retry_count", 0),
+        },
+    )
+
 
 # ---- 侧边栏 ----
 with st.sidebar:
@@ -330,6 +372,10 @@ with st.sidebar:
         new_sid = session_options[selected]
         data = load_session(new_sid)
         if data and data.get("agent_state"):
+            _app_log.info(
+                "切换会话",
+                extra={"from_session": current_session_id, "to_session": new_sid},
+            )
             st.session_state.agent_state = data["agent_state"]
             st.session_state.messages = []
             st.rerun()
@@ -338,6 +384,10 @@ with st.sidebar:
     with col1:
         if st.button("➕ 新建", use_container_width=True):
             new_data = create_session(name="", agent_state=create_initial_state())
+            _app_log.info(
+                "新建会话",
+                extra={"session_id": new_data["session_id"]},
+            )
             st.session_state.agent_state = create_initial_state()
             st.session_state.agent_state["session_id"] = new_data["session_id"]
             st.session_state.agent_state["session_name"] = new_data["session_name"]
@@ -347,6 +397,10 @@ with st.sidebar:
     with col2:
         if st.button("🗑 删除", use_container_width=True):
             if current_session_id:
+                _app_log.info(
+                    "删除会话",
+                    extra={"session_id": current_session_id},
+                )
                 delete_session(current_session_id)
             st.session_state.agent_state = create_initial_state()
             new_data = create_session(name="", agent_state=st.session_state.agent_state)
@@ -541,15 +595,28 @@ for msg in st.session_state.messages:
 if prompt := st.chat_input("描述您的报表需求..."):
     # 拼接上传文件的文本
     uploaded_texts = []
+    uploaded_files_info = []
     if st.session_state.get("uploaded_files"):
         for f in st.session_state.uploaded_files:
             uploaded_texts.append(f"[上传文件: {f['name']}]\n{f['text']}")
+            uploaded_files_info.append({"name": f["name"], "type": f["type"], "length": len(f["text"])})
     if uploaded_texts:
         full_prompt = "\n\n".join(uploaded_texts) + "\n\n---\n用户需求:\n" + prompt
         st.session_state.uploaded_files = []  # 用后即清
     else:
         full_prompt = prompt
 
+    _app_log.info(
+        "收到用户输入",
+        extra={
+            "session_id": current_session_id,
+            "prompt_preview": prompt[:200],
+            "prompt_length": len(prompt),
+            "has_uploaded_files": bool(uploaded_files_info),
+            "uploaded_files": uploaded_files_info,
+        },
+    )
+
     st.session_state.messages.append({"role": "user", "content": prompt})
     with st.chat_message("user"):
         st.markdown(prompt)