refactor: rename require_admin_auth/require_admin_or_agent to require_user_auth/require_user_or_agent

These dependencies check actor type (human user vs agent), not admin
privilege. The old names were misleading and could cause authorization
mistakes when wiring new endpoints. Renamed across all 10 consumer
files along with their local ADMIN_AUTH_DEP / ADMIN_OR_AGENT_DEP
aliases.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/app/api/tasks.py

@@ -20,8 +20,8 @@ from app.api.deps import (
     get_board_for_actor_read,
     get_board_for_user_write,
     get_task_or_404,
-    require_admin_auth,
-    require_admin_or_agent,
+    require_user_auth,
+    require_user_or_agent,
 )
 from app.core.time import utcnow
 from app.db import crud
@@ -100,12 +100,12 @@ TASK_SNIPPET_MAX_LEN = 500
 TASK_SNIPPET_TRUNCATED_LEN = 497
 TASK_EVENT_ROW_LEN = 2
 BOARD_READ_DEP = Depends(get_board_for_actor_read)
-ACTOR_DEP = Depends(require_admin_or_agent)
+ACTOR_DEP = Depends(require_user_or_agent)
 SINCE_QUERY = Query(default=None)
 STATUS_QUERY = Query(default=None, alias="status")
 BOARD_WRITE_DEP = Depends(get_board_for_user_write)
 SESSION_DEP = Depends(get_session)
-ADMIN_AUTH_DEP = Depends(require_admin_auth)
+USER_AUTH_DEP = Depends(require_user_auth)
 TASK_DEP = Depends(get_task_or_404)
 
 
@@ -1449,7 +1449,7 @@ async def create_task(
     payload: TaskCreate,
     board: Board = BOARD_WRITE_DEP,
     session: AsyncSession = SESSION_DEP,
-    auth: AuthContext = ADMIN_AUTH_DEP,
+    auth: AuthContext = USER_AUTH_DEP,
 ) -> TaskRead:
     """Create a task and initialize dependency rows."""
     data = payload.model_dump(exclude={"depends_on_task_ids", "tag_ids", "custom_field_values"})
@@ -1672,7 +1672,7 @@ async def delete_task_and_related_records(
 async def delete_task(
     session: AsyncSession = SESSION_DEP,
     task: Task = TASK_DEP,
-    auth: AuthContext = ADMIN_AUTH_DEP,
+    auth: AuthContext = USER_AUTH_DEP,
 ) -> OkResponse:
     """Delete a task and related records."""
     if task.board_id is None: