fix(automations): 审计行不再显式插 TEXT id，PG identity 下不再丢审计

旧 _audit_row 显式插 uuid 当 audit_log.id：SQLite 下能跑，
生产 PG 的 id 是 BIGINT GENERATED BY DEFAULT AS IDENTITY，
插 TEXT 直接报错、审计行全丢（best-effort 吞掉后无声无息，
#156 留下的已知局限）。修法：INSERT 一律不带 id，让两端
自增/identity 生成；表不存在时先按 PG 口径建、再按 SQLite
口径建、逐个重试——automations 按设计不 import 其它 cloud
模块，所以用先插、失败再按口径重试做方言探测。
单测：test_automation_run_due 4 项（含新增 PG-like 假连接
1 项：只接受不带 id 的 INSERT，旧实现在此应失败）。

cloud/automations.py

@@ -566,26 +566,50 @@ def _automation_quota_exceeded(conn, owner):
 
 
 def _audit_row(conn, project_id, action, detail, now):
-    """best-effort 写审计行：失败不影响自动化运行本身。"""
+    """best-effort 写审计行：失败不影响自动化运行本身。
+
+    旧实现显式插 TEXT uuid 当 id：SQLite 下能跑，但生产 PG 的
+    audit_log.id 是 BIGINT GENERATED BY DEFAULT AS IDENTITY，
+    插 TEXT 直接报错、审计行全丢（best-effort 吞掉后无声无息）。
+    修法：INSERT 一律不带 id，让两端自增/identity 生成；
+    表不存在时先按 PG 口径建、再按 SQLite 口径建、逐个重试，
+    哪边建表成功就用哪边——automations 按设计不 import 其它
+    cloud 模块，所以用“先插、失败再按口径重试”做方言探测，
+    不靠 import 判断后端。
+    """
+    params = ("system", project_id, action, detail, now)
     try:
         conn.execute(
-            "CREATE TABLE IF NOT EXISTS audit_log("
-            "id TEXT PRIMARY KEY, "
-            "user_id TEXT, "
-            "project_id TEXT, "
-            "action TEXT, "
-            "detail TEXT, "
-            "created_at DOUBLE PRECISION)")
-        conn.execute(
-            "INSERT INTO audit_log(id, user_id, project_id, action,"
-            " detail, created_at) VALUES(?, 'system', ?, ?, ?, ?)",
-            (uuid.uuid4().hex, project_id, action, detail, now))
+            "INSERT INTO audit_log(user_id, project_id, action,"
+            " detail, created_at) VALUES(?, ?, ?, ?, ?)", params)
         conn.commit()
+        return
     except Exception:
         try:
             conn.rollback()
         except Exception:
             pass
+    for ddl in (
+            "CREATE TABLE IF NOT EXISTS audit_log("
+            "id BIGINT GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY, "
+            "user_id TEXT, project_id TEXT, action TEXT, detail TEXT, "
+            "created_at DOUBLE PRECISION)",
+            "CREATE TABLE IF NOT EXISTS audit_log("
+            "id INTEGER PRIMARY KEY AUTOINCREMENT, "
+            "user_id TEXT, project_id TEXT, action TEXT, detail TEXT, "
+            "created_at REAL)"):
+        try:
+            conn.execute(ddl)
+            conn.execute(
+                "INSERT INTO audit_log(user_id, project_id, action,"
+                " detail, created_at) VALUES(?, ?, ?, ?, ?)", params)
+            conn.commit()
+            return
+        except Exception:
+            try:
+                conn.rollback()
+            except Exception:
+                pass
 
 
 def run_due_automation(conn, automation_id, now=None):