修复: 灵感模块数据安全 + 建立整体任务图谱DAG

- IDEA-FIX-02: ideas 白名单移除 id/created_at(对标 tasks B-260616-16,防主键/创建时间篡改)
- IDEA-FIX-03: create_idea 加 priority ∈ 0..=3 值域校验(对标 tasks B-260615-15,防越界静默吞)
- docs/todo.md: 建立整体任务图谱(DAG·有方向有状态),整合知识图谱设计+22条待办+G1
- 核销 BUG-260620-05 层1: 已被 F-260619-03 方案①弱化取代(default_with_root 空,reload 不塞 workspace_root),层2 黑名单制仍待决策

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

@@ -119,8 +119,10 @@ impl SettingsRepo {
 pub fn allowed_columns_for(table: &str) -> Option<&'static [&'static str]> {
     Some(match table {
         "ideas" => &[
-            "id", "title", "description", "status", "priority", "score", "tags", "source",
-            "promoted_to", "ai_analysis", "scores", "related_ids", "created_at", "updated_at",
+            // IDEA-FIX-02: id\created_at 不列入 — 主键与创建时间不可通过通用 update_field 改写
+            // (对标 tasks 白名单 B-260616-16 同款防护,防篡改主键/伪造创建时间)
+            "title", "description", "status", "priority", "score", "tags", "source",
+            "promoted_to", "ai_analysis", "scores", "related_ids", "updated_at",
         ],
         "projects" => &[
             "id", "name", "description", "status", "idea_id", "path", "stack", "created_at",