Filter tasks by owner_id via query param

[Navashub]

Description

Currently anyone can see all tasks. Add an owner_id query param to GET /tasks/ so a frontend can fetch only a specific user's tasks.

What to do

• Add an optional owner_id: Optional[int] = None query param to GET /tasks/
• When provided, filter the SQLAlchemy query: .filter(Task.owner_id == owner_id)
• When not provided, return all tasks (existing behaviour)
• Update crud.py to accept owner_id as an optional argument

Acceptance Criteria

• GET /tasks/?owner_id=1 returns only tasks belonging to user 1
• GET /tasks/ (no param) returns all tasks
• Returns an empty list (not an error) if the user has no tasks

Difficulty

🟡 Intermediate