fix(governance): 统一文档访问判定与上下文快照排除计数

补齐 DocumentAccessDecider HTTP 409、projectcontext 私有对话排除统计，并更新整改 gap matrix 与测试报告。

scripts/fix-completed-instance-lifecycle.sql

@@ -0,0 +1,18 @@
+-- 修复「实例 completed 但项目仍为 active」的历史不一致数据。
+-- 用法：
+--   psql "$DATABASE_URL" -f scripts/fix-completed-instance-lifecycle.sql
+-- Dry-run（仅统计）：
+--   psql "$DATABASE_URL" -c "SELECT COUNT(*) FROM projects p JOIN project_workflow_instances i ON i.project_id = p.id AND i.status = 'completed' WHERE p.lifecycle_status <> 'planning';"
+
+BEGIN;
+
+UPDATE projects p
+SET lifecycle_status = 'planning',
+    active_workflow_key = '',
+    updated_at = now()
+FROM project_workflow_instances i
+WHERE i.project_id = p.id
+  AND i.status = 'completed'
+  AND p.lifecycle_status <> 'planning';
+
+COMMIT;