fix(tasks): resolve merge conflict in views.py, unify approval workflow and services

relaxed Pillow requirement to >=12.1.1

improved and added task endpoint docs and testing docs

added full API coverage for task approval workflow

implemented 2-step approval workflow & assign/change status

added permission classes and improved permission checks in views

Added View set w dashboard endpoints and Tasks approval/query service

Added Task model with approval workflow, helper methods and serializers

added comprehensive Week 2 documentation and guidelines

added week2 reqs, did testing and added docs

did testing, updated code and added documentation for the week1 reqs

restructured backend