Add FastAPI application, API endpoints, Celery workers, and Docker configuration

Co-authored-by: christianlouis <361235+christianlouis@users.noreply.github.com>

backend/app/api/v1/endpoints/subscriptions.py

@@ -0,0 +1,35 @@
+"""Subscription and payment endpoints"""
+from typing import List
+from fastapi import APIRouter, Depends, HTTPException, status
+from sqlalchemy.ext.asyncio import AsyncSession
+from sqlalchemy import select
+
+from app.core.database import get_db
+from app.core.deps import get_current_active_user
+from app.models.database_models import User, SubscriptionPlan
+from app.models.schemas import SubscriptionPlanResponse
+
+router = APIRouter()
+
+
+@router.get("/plans", response_model=List[SubscriptionPlanResponse])
+async def list_subscription_plans(
+    db: AsyncSession = Depends(get_db)
+):
+    """List all available subscription plans"""
+    result = await db.execute(
+        select(SubscriptionPlan).where(SubscriptionPlan.is_active == True)
+    )
+    return result.scalars().all()
+
+
+@router.get("/current")
+async def get_current_subscription(
+    current_user: User = Depends(get_current_active_user)
+):
+    """Get current user's subscription details"""
+    return {
+        "tier": current_user.subscription_tier,
+        "status": current_user.subscription_status,
+        "expires_at": current_user.subscription_expires_at
+    }