fix(memory): 读侧过 status 闸 —— 软删行不再被检索、不再进面板

整理（tidy）与入库前审查（D3）都只做软动作：status 改 merged/archived，
正文一个字不改、行一行不删。因此只要有一条「能看到什么记忆」的读路径
漏了 status 闸，清理就等于白清 —— 生产库上那 10 条 merged 行就是反例。

- store.go：ListByPersona / List 加 status='active'
- rules.go：ListScope / ListProject 加 status='active'
- Get 刻意不过闸（撤销软合并要先读得到被吸收的行），并在注释里写明
- gateway/admin.go collectMemories 只加注释：口径只有一处，不重复过滤

验证：go build ./... + go vet 绿；memory 包全量测试绿；
新增 status_gate_test.go（4 条读路径逐条断言 + Retriever 端到端
「内容逐字相同的两条，软合并后只召回一条」+ Get 反向护栏）；
用 -overlay 把闸门变异成恒真 ⇒ 5 个读路径用例与检索端到端用例全红。

internal/runtime/memory/rules.go

@@ -82,8 +82,8 @@ func (s *Store) ListScope(ctx context.Context, scope Scope, personaID string) ([
 	}
 	rows, err := s.db.QueryContext(ctx, `SELECT id, persona_id, role_id, project_id, scope, kind,
 		content, tags, confidence, source_conversation, created_at, updated_at,
-		decay_weight FROM memory_items WHERE scope = ?
-		ORDER BY created_at DESC, rowid DESC`, string(scope))
+		decay_weight FROM memory_items WHERE scope = ? AND status = ?
+		ORDER BY created_at DESC, rowid DESC`, string(scope), string(tidyStatusActive))
 	if err != nil {
 		return nil, fmt.Errorf("memory: list scope items: %w", err)
 	}
@@ -103,8 +103,8 @@ func (s *Store) ListProject(ctx context.Context, projectID string) ([]MemoryItem
 	}
 	rows, err := s.db.QueryContext(ctx, `SELECT id, persona_id, role_id, project_id, scope, kind,
 		content, tags, confidence, source_conversation, created_at, updated_at,
-		decay_weight FROM memory_items WHERE project_id = ?
-		ORDER BY created_at DESC, rowid DESC`, projectID)
+		decay_weight FROM memory_items WHERE project_id = ? AND status = ?
+		ORDER BY created_at DESC, rowid DESC`, projectID, string(tidyStatusActive))
 	if err != nil {
 		return nil, fmt.Errorf("memory: list project items: %w", err)
 	}