fix(web): 修复概览/表注释展示为空问题，重整空字段与冗余字段 tab

后端
- models.py: OverviewStats 补充 mid_empty_fields / standards_applied 字段，
  避免被 routes.py 的字段过滤机制误删
- orchestrator.py: _build_overview 修正 nested overview_meta 取值（三层嵌套，
  之前一直兜底到 0 → 表/字段总数显示 0)
- step4_empty_fields.py: 修复 table_comment 始终为空（之前从列级 row 取
  table_comment，应从 table_summary 取），新增 per_table.total_fields 与
  field_record 用同一份 table_comment_map

前端 (index.html / style.css)
- 隐藏历史记录入口（保留后端接口，便于以后恢复）
- 移除「中空字段」KPI 卡片（位于中间不符合浏览习惯）
- 大范围空字段 tab：
  * 字段明细（平铺：等级/表名/表注释/字段名/字段注释/类型/空值数/空值率）
    上移到主视图位置
  * 按表统计下移为辅助视图，表名+表注释合并到一列避免错位
- 冗余字段 tab：把 prop 改成与后端实际数据一致的
  field/table_count/classification/reasoning/recommendation/source，并
  给 llm_failed / true_redundancy / suspicious / common_business /
  common_base 各加色 tag 显著标识
- 修复"\"LLM 失败\""导致的 template compile 错误引发的白屏
  （HTML 属性里 \ 不会被当 JS 转义，把 " 换成「 」即可）
- .app-main 宽度 1400 → 1800px，table 更舒展

web/core/models.py

@@ -99,9 +99,11 @@ class OverviewStats(BaseModel):
     total_tables: int = 0
     total_fields: int = 0
     high_empty_fields: int = 0
+    mid_empty_fields: int = 0
     missing_comments: int = 0
     length_issues: int = 0
     standard_violations: int = 0
+    standards_applied: int = 0
     merge_candidates: int = 0
     redundancy_fields: int = 0
     executed_at: Optional[datetime] = None

web/core/orchestrator.py

@@ -345,7 +345,11 @@ def _generate_reports(run_dir: Path, sections: dict, overview: dict,
 # ── Overview 构造 ──
 def _build_overview(sections: dict, cfg: DBConfig) -> dict:
     """从各 section 汇总概览数据"""
-    overview_meta = sections.get("overview_meta", {})
+    # step1 返回的 data 嵌套了三层：sections["overview_meta"] =
+    #   {"data_dictionary": [...], "table_summary": [...], "overview_meta": {total_tables, total_fields, ...}}
+    # 统计字段在最内层 overview_meta 里
+    overview_meta_root = sections.get("overview_meta", {})
+    overview_meta = overview_meta_root.get("overview_meta", overview_meta_root) if isinstance(overview_meta_root, dict) else {}
     empty = sections.get("empty_fields", {}).get("summary", {})
     missing = sections.get("missing_comments", {}).get("summary", {})
     length = sections.get("length_issues", {}).get("summary", {})

web/core/step_impl/step4_empty_fields.py

@@ -46,6 +46,21 @@ def run_step4(cfg: DBConfig, log: Callable | None = None,
     for row in columns:
         by_table[row["table_name"]].append(row)
 
+    # 表级注释来自 table_summary（INFORMATION_SCHEMA.TABLES），
+    # 列级 row（COLUMNS）没有 table_comment 字段
+    table_comment_map: dict[str, str] = {}
+    for t in table_summary:
+        name = t.get("table_name") or t.get("TABLE_NAME")
+        if not name:
+            continue
+        comment = (
+            t.get("table_comment")
+            or t.get("TABLE_COMMENT")
+            or ""
+        )
+        if comment:
+            table_comment_map[name] = comment
+
     loader = get_sql_loader()
     high_count = 0
     mid_count = 0
@@ -118,7 +133,7 @@ def run_step4(cfg: DBConfig, log: Callable | None = None,
                     empty_rate = empty_count / row_count if row_count else 0
                     field_record = {
                         "table_name": table,
-                        "table_comment": col.get("table_comment", ""),
+                        "table_comment": table_comment_map.get(table, ""),
                         "column_name": col["column_name"],
                         "data_type": col["data_type"],
                         "column_type": col["column_type"],
@@ -140,10 +155,12 @@ def run_step4(cfg: DBConfig, log: Callable | None = None,
 
                 if high_in_table or mid_in_table:
                     tables_with_issues.add(table)
+                    total_fields_in_table = len(by_table[table])
                     per_table.append({
                         "table_name": table,
-                        "table_comment": by_table[table][0].get("table_comment", ""),
+                        "table_comment": table_comment_map.get(table, ""),
                         "total_rows": row_count,
+                        "total_fields": total_fields_in_table,
                         "high_empty_fields": high_in_table,
                         "mid_empty_fields": mid_in_table,
                         "high_count": len(high_in_table),

web/static/style.css

@@ -67,7 +67,8 @@ body {
 }
 
 .app-main {
-    max-width: 1400px;
+    width: 100%;
+    max-width: 1800px;
     margin: 0 auto;
     padding: 20px;
 }