chore(quality): apply ruff autofixes and formatting (223 fixes, regression-free: 118/118 tests pass)

app/schemas/tag.py

@@ -3,7 +3,6 @@
 from __future__ import annotations
 
 from datetime import datetime
-from typing import Optional
 
 from pydantic import BaseModel, ConfigDict, Field
 
@@ -28,7 +27,7 @@ class TagOut(BaseModel):
     color: str
     created_at: datetime
     updated_at: datetime
-    deleted_at: Optional[datetime] = None
+    deleted_at: datetime | None = None
 
 
 class TagLinkCreate(BaseModel):
@@ -51,7 +50,7 @@ class TagLinkOut(BaseModel):
     parent_id: int
     created_at: datetime
     updated_at: datetime
-    deleted_at: Optional[datetime] = None
+    deleted_at: datetime | None = None
 
 
 __all__ = ["TagCreate", "TagLinkCreate", "TagLinkOut", "TagOut"]