Add landing page, referral system, usage quotas, search API management, and yearly pricing

- Separate workspace landing from login for better UX
- Referral system rewards both parties with Pro days
- Quota enforcement prevents abuse without breaking endpoints
- 7-day free trial with auto-downgrade on expiry
- Admin-managed search provider config (SearXNG, Bing)
- 15% discount on annual subscriptions
- MCP search server wrapping opencode search
- Fix discovery module field name mismatch causing 422

backend/app/api/v1/auth.py

@@ -10,6 +10,11 @@ from app.core.security import hash_password, verify_password, create_access_toke
 from pydantic import BaseModel, EmailStr
 from datetime import datetime, timedelta
 from app.services.admin import AdminService
+from app.models.subscription import Subscription
+from app.api.v1.referral import apply_referral
+import logging
+
+logger = logging.getLogger(__name__)
 
 router = APIRouter()
 
@@ -18,6 +23,7 @@ class RegisterRequest(BaseModel):
     phone: str
     password: str
     username: str = ""
+    ref_code: str = ""
 
 
 class LoginResponse(BaseModel):
@@ -47,11 +53,28 @@ async def register(data: RegisterRequest, request: Request, db: AsyncSession = D
         phone=data.phone,
         username=data.username or data.phone,
         password_hash=hash_password(data.password),
-        tier="free",
+        tier="pro",
     )
     db.add(user)
     await db.flush()
 
+    trial_end = datetime.utcnow() + timedelta(days=settings.TRIAL_DAYS)
+    sub = Subscription(
+        user_id=user.id,
+        plan="pro_trial",
+        status="active",
+        started_at=datetime.utcnow(),
+        expires_at=trial_end,
+    )
+    db.add(sub)
+
+    if data.ref_code:
+        try:
+            from app.api.v1.referral import do_claim_referral
+            await do_claim_referral(data.ref_code, str(user.id), db)
+        except Exception as e:
+            logger.warning(f"Referral claim failed: {e}")
+
     client_ip = request.client.host if request.client else None
     await AdminService(db).log_usage(str(user.id), "user.register", {"phone": data.phone}, ip=client_ip)
 
@@ -89,6 +112,20 @@ async def login(
     client_ip = request.client.host if request.client else None
     await AdminService(db).log_usage(str(user.id), "user.login", {"login_id": login_id}, ip=client_ip)
 
+    if user.tier == "pro":
+        sub_result = await db.execute(
+            select(Subscription).where(
+                Subscription.user_id == user.id,
+                Subscription.plan == "pro_trial",
+                Subscription.status == "active",
+            )
+        )
+        trial_sub = sub_result.scalar_one_or_none()
+        if trial_sub and trial_sub.expires_at and trial_sub.expires_at < datetime.utcnow():
+            trial_sub.status = "expired"
+            user.tier = "free"
+            await db.flush()
+
     return LoginResponse(
         access_token=create_access_token({"sub": str(user.id), "tier": user.tier, "role": user.role}),
         refresh_token=create_refresh_token({"sub": str(user.id)}),
@@ -178,6 +215,20 @@ async def get_me(
     if not user:
         raise HTTPException(status_code=404, detail="User not found")
 
+    trial_days_left = 0
+    if user.tier == "pro":
+        sub_result = await db.execute(
+            select(Subscription).where(
+                Subscription.user_id == user.id,
+                Subscription.plan == "pro_trial",
+                Subscription.status == "active",
+            )
+        )
+        trial_sub = sub_result.scalar_one_or_none()
+        if trial_sub and trial_sub.expires_at:
+            remaining = (trial_sub.expires_at - datetime.utcnow()).days
+            trial_days_left = max(0, remaining)
+
     return {
         "id": str(user.id),
         "phone": user.phone,
@@ -186,6 +237,7 @@ async def get_me(
         "role": user.role,
         "settings": user.settings,
         "created_at": user.created_at.isoformat() if user.created_at else None,
+        "trial_days_left": trial_days_left,
     }