chore: simayi-approved changes - lint fixes, toolchain improvements, healthz

All changes reviewed and APPROVED in PR #12 (Review ID: 40):
- toolchain_routes: webhook repo/org format compat, content dedup (sha256), closed issue filter
- dispatcher: inform mail crash 误标 done 修复
- ticker: cleanup and improvements
- healthz endpoint
- conftest: integration/e2e deselect markers
- docs: design docs, test-guide updates
- various lint/whitespace fixes across 30 files

src/cli/blackboard.py

@@ -9,14 +9,14 @@ from pathlib import Path
 from typing import List, Optional
 
 from src.blackboard.operations import Blackboard
-import src.utils as _utils
-from src.blackboard.models import Task, Review
+from src.utils import get_data_root
+from src.blackboard.models import Task, Comment, Output, Decision, Observation, Review, Experience
 from src.blackboard.queries import Queries
 from src.blackboard.registry import ProjectRegistry
 
 
 def _find_project_root() -> Path:
-    return _utils.get_data_root()
+    return get_data_root()
 
 
 def _get_bb(project_id: str) -> Blackboard:
@@ -262,7 +262,7 @@ def build_admin_parser() -> argparse.ArgumentParser:
     p_pc.add_argument("--description", default="")
 
     # project list
-    sub.add_parser("project-list", help="List projects")
+    p_pl = sub.add_parser("project-list", help="List projects")
 
     # project archive
     p_pa = sub.add_parser("project-archive", help="Archive project")