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/models/__init__.py

@@ -14,6 +14,8 @@ from .system_config import SystemConfig
 from .translation_quota import TranslationQuota
 from .certification import Certification, CertType, CertStatus
 from .invoice import Invoice, InvoiceType, InvoiceStatus
+from .referral import ReferralCode, Referral
+from .search_provider import SearchProvider
 
 __all__ = [
     "User", "Product",
@@ -32,4 +34,6 @@ __all__ = [
     "TranslationQuota",
     "Certification", "CertType", "CertStatus",
     "Invoice", "InvoiceType", "InvoiceStatus",
+    "ReferralCode", "Referral",
+    "SearchProvider",
 ]

backend/app/models/referral.py

@@ -0,0 +1,26 @@
+from sqlalchemy import Column, String, Integer, DateTime, ForeignKey, Boolean
+from sqlalchemy.dialects.postgresql import UUID
+from datetime import datetime
+from app.database import Base
+import uuid
+
+
+class ReferralCode(Base):
+    __tablename__ = "referral_codes"
+
+    id = Column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
+    user_id = Column(UUID(as_uuid=True), nullable=False, index=True)
+    code = Column(String(20), unique=True, nullable=False, index=True)
+    created_at = Column(DateTime, default=datetime.utcnow)
+
+
+class Referral(Base):
+    __tablename__ = "referrals"
+
+    id = Column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
+    referrer_id = Column(UUID(as_uuid=True), nullable=False, index=True)
+    referred_id = Column(UUID(as_uuid=True), nullable=False, unique=True)
+    code = Column(String(20), nullable=False)
+    reward_days = Column(Integer, default=15)
+    status = Column(String(20), default="completed")
+    created_at = Column(DateTime, default=datetime.utcnow)

backend/app/models/search_provider.py

@@ -0,0 +1,20 @@
+from sqlalchemy import Column, String, Integer, DateTime, Boolean, Text
+from sqlalchemy.dialects.postgresql import UUID, JSONB
+from datetime import datetime
+from app.database import Base
+import uuid
+
+
+class SearchProvider(Base):
+    __tablename__ = "search_providers"
+
+    id = Column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
+    name = Column(String(100), nullable=False)
+    provider_type = Column(String(50), nullable=False)
+    api_key = Column(Text, nullable=True)
+    api_endpoint = Column(String(500), nullable=True)
+    extra_config = Column(JSONB, default={})
+    priority = Column(Integer, default=0)
+    enabled = Column(Boolean, default=True)
+    created_at = Column(DateTime, default=datetime.utcnow)
+    updated_at = Column(DateTime, default=datetime.utcnow, onupdate=datetime.utcnow)