✨ feat: add auto table creation and per-PK sync verification

- Add new Access table mappings for transmitter contracts (25/26年变送器) and tube bending workshop (弯管车间烘洗)
- Add auto-create target table from Access schema when table does not exist (db_utils + init_full_sync)
- Implement per-primary-key verification in incremental sync: verify deletes are gone and inserts are present before marking Synced=1
- Add post-commit re-verification with Synced rollback on failure for automatic retry
- Batch IN clause parameters to stay under SQL Server limit
- Adjust poll interval from 5s to 30s
- Improve IDENTITY_INSERT cleanup in finally blocks

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

db_utils.py

@@ -1,7 +1,82 @@
 # db_utils.py
 import pyodbc
+import datetime
+import decimal
 from config import SQL_SERVER_CONN, ACCESS_DRIVER
 
+
+# ================= 表存在性检查 & 自动建表 =================
+
+def table_exists(cursor, schema, table):
+    """检查 SQL Server 表是否存在"""
+    query = """
+        SELECT COUNT(*)
+        FROM sys.tables t
+        JOIN sys.schemas s ON t.schema_id = s.schema_id
+        WHERE s.name = ? AND t.name = ?
+    """
+    cursor.execute(query, (schema, table))
+    return cursor.fetchone()[0] > 0
+
+
+def ensure_schema(cursor, schema):
+    """确保 schema 存在，不存在则创建"""
+    cursor.execute("SELECT SCHEMA_ID(?)", (schema,))
+    if cursor.fetchone()[0] is None:
+        cursor.execute(f"CREATE SCHEMA [{schema}]")
+
+
+def _access_col_to_sql(col_info, pk_col):
+    """将 Access 列描述 (cursor.description 元组) 转为 SQL Server 列定义
+
+    Access ODBC 驱动的 type_code 是 Python 类型对象:
+      int              → INT
+      str              → NVARCHAR(size)  (size > 4000 时为 Memo 字段 → NVARCHAR(MAX))
+      datetime.datetime → DATETIME
+      float            → FLOAT
+      decimal.Decimal  → DECIMAL(p,s)
+      bool             → BIT
+    """
+    col_name, type_code, _, size, precision, scale, nullable = col_info
+    is_pk = (col_name == pk_col)
+
+    if type_code is int:
+        sql_type = "INT"
+        if is_pk:
+            sql_type += " IDENTITY(1,1) PRIMARY KEY"
+    elif type_code is float:
+        sql_type = "FLOAT"
+    elif type_code is bool:
+        sql_type = "BIT"
+    elif type_code is datetime.datetime:
+        sql_type = "DATETIME"
+    elif type_code is decimal.Decimal:
+        sql_type = f"DECIMAL({precision or 18}, {scale or 0})"
+    elif type_code is str:
+        # size > 4000 → Access Memo 字段，用 NVARCHAR(MAX)
+        if not size or size <= 0 or size > 4000:
+            sql_type = "NVARCHAR(MAX)"
+        else:
+            sql_type = f"NVARCHAR({size})"
+        if is_pk:
+            sql_type += " PRIMARY KEY"
+    else:
+        sql_type = "NVARCHAR(255)"
+        if is_pk:
+            sql_type += " PRIMARY KEY"
+
+    return f"[{col_name}] {sql_type}"
+
+
+def create_table_from_access(sql_cursor, target_schema, target_table,
+                             acc_description, pk_col):
+    """根据 Access cursor.description 在 SQL Server 自动建表"""
+    col_defs = [_access_col_to_sql(col, pk_col) for col in acc_description]
+    full_name = fmt_table(target_schema, target_table)
+    col_str = ",\n    ".join(col_defs)
+    create_sql = f"CREATE TABLE {full_name} (\n    {col_str}\n)"
+    sql_cursor.execute(create_sql)
+
 def get_sql_conn():
     """获取 SQL Server 连接"""
     # 显式添加 TrustServerCertificate=yes 以兼容 ODBC Driver 18+