Refactor: Auth & Identity System v1.4

- Fix: Resolved SQLAlchemy Mapper error for 'UserVehicle' using string-based relationships.
- Fix: Fixed Postgres Enum case sensitivity issue for 'userrole' (forcing lowercase 'user').
- Fix: Resolved ImportError for 'create_access_token' in security module.
- Feature: Implemented 2-step registration protocol (Lite Register -> KYC Step).
- Data: Added bank-level KYC fields (mother's name, ID/Driver/Boat/Pilot license expiry and categories).
- Business: Applied private fleet isolation (is_transferable=False for individual orgs).
- Docs: Updated Grand Master Book to v1.4 and added Developer Pitfalls guide.

backend/app/models/vehicle.py

@@ -44,7 +44,7 @@ class Vehicle(Base):
     __tablename__ = "vehicles"
     __table_args__ = {"schema": "data"}
     id = Column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
-    current_company_id = Column(Integer, ForeignKey("data.companies.id"))
+    current_company_id = Column(Integer, ForeignKey("data.organizations.id"))
     brand_id = Column(Integer, ForeignKey("data.vehicle_brands.id"))
     model_name = Column(String(100))
     engine_spec_id = Column(Integer, ForeignKey("data.engine_specs.id"))
@@ -54,14 +54,10 @@ class Vehicle(Base):
     current_rating_pct = Column(Integer, default=100)
     total_real_usage = Column(Numeric(15, 2), default=0)
     created_at = Column(DateTime(timezone=True), server_default=func.now())
+    
     engine_spec = relationship("EngineSpec", back_populates="vehicles")
     service_records = relationship("ServiceRecord", back_populates="vehicle", cascade="all, delete-orphan")
-
-# --- KOMPATIBILITÁSI RÉTEG A RÉGI KÓDOKHOZ ---
-VehicleOwnership = Vehicle
-VehicleModel = Vehicle
-VehicleVariant = Vehicle
-VehicleCategory = VehicleBrand  # JAVÍTVA: Nagy "B" betűvel
+    current_org = relationship("Organization", back_populates="vehicles")
 
 class ServiceRecord(Base):
     __tablename__ = "service_records"
@@ -74,4 +70,18 @@ class ServiceRecord(Base):
     repair_quality_pct = Column(Integer, default=100)
 
     vehicle = relationship("Vehicle", back_populates="service_records")
-    provider = relationship("ServiceProvider", back_populates="records") # JAVÍTVA
+    provider = relationship("ServiceProvider", back_populates="records")
+
+class OrganizationMember(Base):
+    __tablename__ = "organization_members"
+    __table_args__ = {"schema": "data"}
+    id = Column(Integer, primary_key=True, index=True)
+    organization_id = Column(Integer, ForeignKey("data.organizations.id"), nullable=False)
+    user_id = Column(Integer, ForeignKey("data.users.id"), nullable=False)
+    role = Column(String, default="driver") 
+
+    organization = relationship("Organization", back_populates="members")
+
+# --- KOMPATIBILITÁSI RÉTEG ---
+UserVehicle = Vehicle 
+VehicleOwnership = Vehicle