新增: 知识图谱Phase1数据层(父②) + 修复 idea list_by_query 占位符(父⑤⑤.1)

父② 数据层(V29):
- migrate_v29: tasks +queue/parent_id/content_json + task_links 表+双索引(幂等对标 v14/v24)
- TaskRecord 加 3 字段(15→18 列,INSERT/SELECT×6/from_row/struct 同步)+ 8 构造点补默认
- TaskLinkRepo(新文件,CRUD + 循环依赖 BFS depends_on 链检测,14 测)
- task_repo list_by_query queue/parent_id 筛选 + get_children + 聚合计数(10 测)
- queue DEFAULT 'todo' 向后兼容;task_links 软删保留(无 ON DELETE)

idea_repo list_by_query 占位符修复(父⑤⑤.1 引入的潜伏 bug):
- 加 deleted_at IS NULL 恒带后 where_clauses.len()+1 偏移 → 非空 status/keyword 查询 rusqlite 错误
- 改 params_vec.len()+1(对标 task_repo ②.2 同款修复,父② agent 发现)

df-storage 96 lib + 11 集成测试全过。

crates/df-storage/src/crud/mod.rs

@@ -6,6 +6,7 @@
 //! - [`mod@settings`]:SettingsRepo + 列白名单(allowed_columns_for/validate_column_name/is_allowed_column)
 //! - [`mod@project_repo`]:ProjectRepo/BranchRepo/ReleaseRepo/WorkflowRepo/NodeExecutionRepo
 //! - [`mod@task_repo`]:TaskRepo(含 advance_status_atomic 状态机收口)
+//! - [`mod@task_link_repo`]:TaskLinkRepo(任务横向关联 task_links,V29,知识图谱 Phase 1)
 //! - [`mod@conversation_repo`]:AiProviderRepo/AiConversationRepo/AiToolExecutionRepo
 //! - [`mod@idea_repo`]:IdeaRepo/KnowledgeRepo/KnowledgeEventsRepo + 向量工具
 //! - [`mod@idea_eval_repo`]:IdeaEvalRepo(灵感评估历史追加型审计表 idea_evaluations,V22)
@@ -20,6 +21,7 @@ mod idea_repo;
 mod message_repo;
 mod project_repo;
 mod settings;
+mod task_link_repo;
 mod task_repo;
 
 pub use conversation_repo::*;
@@ -28,6 +30,7 @@ pub use idea_repo::*;
 pub use message_repo::*;
 pub use project_repo::*;
 pub use settings::*;
+pub use task_link_repo::*;
 pub use task_repo::*;
 
 // ============================================================
@@ -293,6 +296,7 @@ mod baseline_tests {
         let _ = IdeaRepo::new(&db);
         let _ = ProjectRepo::new(&db);
         let _ = TaskRepo::new(&db);
+        let _ = TaskLinkRepo::new(&db);
         let _ = BranchRepo::new(&db);
         let _ = ReleaseRepo::new(&db);
         let _ = WorkflowRepo::new(&db);