FLAG-1 unified task_attempts schema (single canonical DDL + 3-shape migration)

User decision 2026-11-05: unified schema, rejecting the rehearsal
runtime column-union workaround and a ledger rename. One definition
(cloud.attempt_ledger.TASK_ATTEMPTS_DDL, 12 columns) shared by
cloud.attempts and cloud.db.POSTGRES_SCHEMA; ensure builds the
unified table fresh and migrates old resume, gap-3 ledger, and
rehearsal shapes in place with rows intact. aggregate counts
ledger rows only (outcome NULL = resume row, never counted).
SQLite verified by 8 new tests; Postgres real-DB upgrade path
explicitly NOT verified (see batch summary). Local commit only:
no merge, no push, no deploy.

cloud/ledger_onboarding.py

@@ -21,9 +21,10 @@
    报告：表齐但钩子关 ≠ 就绪，钩子开但表不齐 ≠ 就绪。
 3. DDL 清单不另造：清单直接引用 attempt_ledger.PG_DDL
    与 attempt_hook.PG_MARKER_DDL 两个常量（本模块不
-   复制 DDL 文本，复制就会漂移）。另含 gap 3 旧表升级句
-   attempt_ledger.OLD_TABLE_ALTER（仅当旧 DDL 建过表时
-   需要；gap 3 未合并，生产尚无旧表，属防御项）。
+   复制 DDL 文本，复制就会漂移）。老形态表升级走
+   attempt_ledger.ensure_task_attempts_table 的统一列补齐
+   （仅当老形态建过表时需要；属防御项，PG 真实库升级
+   路径未实证）。
 4. 校验函数 verify_ledger_ready(conn)：只读探针——查两
    张表的存在与必需列，不建表、不写行（读路径绝不改
    schema，与 metrics-report 端点的只读纪律一致）。
@@ -42,11 +43,14 @@ from cloud.attempt_hook import PG_MARKER_DDL as _PG_MARKER_DDL
 from cloud.attempt_ledger import OLD_TABLE_ALTER as _OLD_TABLE_ALTER
 from cloud.attempt_ledger import PG_DDL as _LEDGER_PG_DDL
 
-# 必需列：缺任一列即视为表不齐（旧 DDL 建的表缺
-# corrects_attempt_no 时走 OLD_TABLE_ALTER 补列）。
+# 必需列：统一 schema 的全部 12 列；缺任一列即视为表
+# 不齐（老形态建的表由 ensure_task_attempts_table 补齐
+# 缺失列后复核，不再只补 corrects_attempt_no 一列）。
 LEDGER_REQUIRED_COLUMNS = (
     "task_id", "attempt_no", "outcome", "is_defect",
-    "defect_category", "created_at", "corrects_attempt_no",
+    "defect_category", "corrects_attempt_no", "kind",
+    "interrupted_reason", "checkpoint_round", "result_text",
+    "error_text", "created_at",
 )
 MARKER_REQUIRED_COLUMNS = ("task_id", "origin", "queued_at")
 
@@ -72,12 +76,13 @@ LEDGER_DDL_CHECKLIST = (
     },
     {
         "step": 3,
-        "action": "仅当表由 gap 3 旧 DDL 建过时：执行"
-                  " attempt_ledger.OLD_TABLE_ALTER 补"
-                  " corrects_attempt_no 列（gap 3 未合并，"
-                  "生产正常路径跳过此步）",
-        "ddl_source": "cloud.attempt_ledger.OLD_TABLE_ALTER",
-        "verify": "task_attempts 含 corrects_attempt_no 列",
+        "action": "仅当表已由老形态（旧恢复 DDL、gap 3 台账 DDL"
+                  " 或演练形态）建过时：经 attempt_ledger."
+                  "ensure_task_attempts_table 补齐缺失的统一列"
+                  "（SQLite 已实测；PG 真实库升级路径未实证，"
+                  "生产 PG 上执行前须先在真实 PG 上验证）",
+        "ddl_source": "cloud.attempt_ledger.TASK_ATTEMPTS_DDL",
+        "verify": "task_attempts 含统一 schema 全部 12 列",
     },
     {
         "step": 4,