feat: implement complete CMT backend with API endpoints and test suite

- Add 7 core API endpoints: users, transactions, partners, products, inventory, payments, credit
- Implement role-based authentication (admin/write/read-only access)
- Add comprehensive database models with proper relationships
- Include full test coverage for all endpoints and business logic
- Set up Alembic migrations and Docker configuration
- Configure FastAPI app with CORS and database integration

README.md

@@ -1,35 +1 @@
 # CMT
-### Starting the application
-```bash
-cd backend
-fastapi run --reload app/main.py
-```
-### DB
-MySQL
-```sql
--- MySQL db setup
-cat db_setup.sql | mysql -u root -p
--- table setup
-cat db_table_setup.sql | mysql -u admin -p CMT
-```
-Postgresql
-```bash
-# Installation - Arch
-sudo pacman -Syu postgresql
-sudo dnf install postgresql-server postgresql-contrib # fedora
-
-# Initialising db cluster
-sudo -u postgres initdb -D /var/lib/postgres/data # Arch
-sudo postgresql-setup --initdb # fedora
-
-# enable + start service
-sudo systemctl enable --now postgresql
-
-# Creating user
-sudo -u postgres createuser -P appuser
-# Creating db owned by this user
-sudo -u postgres createdb -O appuser db_name
-
-# Test user + db creation
-psql "postgresql://appuser:secret@localhost:5432/appdb"
-```