feat: 智能体详情新增「最近对话」列表，完善推荐问题与任务深链配置

- 新增 AgentRecentChats 组件，在智能体详情面板底部按 agent_id 展示最近对话
- 调整问答/智能体侧边栏与最近对话列表展示逻辑
- 补充 dashboard-input、task-deeplink 相关配置与线程工具方法
- 后端推荐问题接口标签处理及 position_sync 微调，新增相关测试

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

offline-backend-20260512/backend/CLAUDE.md

@@ -393,7 +393,10 @@ query-time type, `recommended_question`.
 Sync only ever adds/removes `origin='position'` rows, so a user's own
 favorites/subscriptions are never clobbered. Default sets (no binding for a
 type): agents = built-ins (`user_id IS NULL`); skills = empty (square stays
-full, nothing added to 我的); scheduled tasks = empty; questions = unrestricted.
+full, nothing added to 我的); scheduled tasks = empty; questions = **untagged
+only** (默认岗位 / 无标签绑定 只看到未打标的题目；打标的题目只在绑定了对应标签的
+岗位展示 — the router interprets `resolve_visible → None` as "show only untagged",
+not "show everything").
 `origin`/`position_id` columns were added to `agent_favorites` and
 `scheduled_task_subscriptions` — see migration `20260616_01` +
 `scripts/sql/column_additions_mysql.sql`. The running app also auto-adds these
@@ -415,8 +418,12 @@ unassigned users inherit, else `null`); powers the top-bar 岗位 label
 changes: `GET /api/recommended-questions` is now
 filtered by the caller's position (`?all=1` bypasses for admin management) and
 admin can tag questions via `/api/tags/assignments/recommended_question/{id}`.
-Each listed question now carries its assigned `tags` (bulk-attached via
-`tag_store.list_assignments`), and the list accepts a repeatable `tag_ids`
+**Default-position rule**: tags are bulk-attached to **all** questions first,
+then the visibility filter applies — a position binding recommended_question 标签
+sees only those tagged questions; a 默认岗位 / 无绑定 (`resolve_visible → None`)
+sees only the **untagged** questions (打标的题目不再泄漏到默认岗位). `?all=1`
+(admin management) skips this filter and returns every question with its tags.
+The list also accepts a repeatable `tag_ids`
 OR-filter — so the 推荐问题配置 page can display per-question 标签 and search by
 them (frontend `RecommendedQuestionsPage` + `TagSearchBar`). Tests:
 `tests/test_recommended_questions_tags.py`.