fix(task-deeplink): 共享任务对话的 md/产物按对话创建者解析路径,修复切换账号后找不到文件

xdfx/rwfx/3qfx 任务深链对话按 metadata.taskId 全局共享、不区分用户,但生成的
md/artifacts 与上传文件物理存在 users/{user_id}/threads/{thread_id}/ 下,user_id
之前取当前登录账号。导致 A 账号生成的文件,B 账号打开同一共享对话时后端去
users/B/ 找 → 404「找不到」。

新增 deerflow/runtime/thread_paths.py(resolve_path_user_id /
aresolve_path_user_id):带 taskId 的共享对话统一解析到对话创建者
(threads_meta.user_id),个人对话仍走当前登录(行为不变)。在所有线程文件路径关口替换:
写入源 ThreadDataMiddleware、present_files、uploads(manager+middleware+router)、
产物读写(path_utils → artifacts/skills router)、嵌入式 client.get_artifact。
正向结果进程内缓存;无 DB/内存态/无行均安全回退到当前登录。

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

offline-backend-20260512/backend/CLAUDE.md

@@ -459,6 +459,7 @@ Operators upgrading an existing DB run the whole file (`USE <db>;` then execute)
 - Physical: `backend/.deer-flow/users/{user_id}/threads/{thread_id}/user-data/...`, `deer-flow/skills/`
 - Translation: `replace_virtual_path()` / `replace_virtual_paths_in_command()`
 - Detection: `is_local_sandbox()` checks `sandbox_id == "local"`
+- **`{user_id}` for path resolution = `resolve_path_user_id(thread_id)`, NOT the current login.** Task-deeplink conversations (rwfx/3qfx/xdfx, `threads_meta.metadata.taskId`) are shared across all users (see the `taskId` escape branches in `thread_meta/sql.py`), but generated files/uploads live under a *per-user* dir. Resolving by current login meant account B opening a shared task conversation 404'd on the md/artifacts account A generated ("切换账号后生成的文件找不到"). `deerflow/runtime/thread_paths.py` (`resolve_path_user_id` sync / `aresolve_path_user_id` async) resolves a task-shared thread to its **creator** (`threads_meta.user_id`), so every account reads/writes the same physical directory; personal threads resolve to the current login unchanged (no behavior change). Wired at every thread-path seam: write source `ThreadDataMiddleware.before_agent` (drives all sandbox writes via `thread_data` paths), `present_file_tool`, `uploads/manager.get_uploads_dir` + `uploads_middleware` + uploads router, artifact serving (`path_utils.{a,}resolve_thread_virtual_path` → artifacts/skills routers), embedded `client.get_artifact`. Positive (taskId→creator) results are cached process-wide (immutable mapping); any failure / memory-mode store / missing row falls back to the current login. **Caveat**: files a *non-creator* wrote into a shared thread before this fix stay orphaned under that writer's dir (no data loss); all new writes consolidate under the creator. Tests: `tests/test_thread_paths_owner.py`.
 
 **Sandbox Tools** (in `packages/harness/deerflow/sandbox/tools.py`):
 - `bash` - Execute commands with path translation and error handling