feat(faq): refine category icons and project faq flows

backend/app/models/faq_category.py

@@ -4,7 +4,7 @@ from typing import Optional
 import uuid
 from datetime import datetime
 
-from sqlalchemy import Boolean, DateTime, ForeignKey, String, Text, UniqueConstraint, func
+from sqlalchemy import DateTime, ForeignKey, String, Text, UniqueConstraint, func
 from sqlalchemy.dialects.postgresql import UUID
 from sqlalchemy.orm import Mapped, mapped_column
 
@@ -20,7 +20,7 @@ class FaqCategory(Base):
     name: Mapped[str] = mapped_column(String(100), nullable=False)
     description: Mapped[Optional[str]] = mapped_column(Text, nullable=True)
     sort_order: Mapped[int] = mapped_column(nullable=False, default=0)
-    is_active: Mapped[bool] = mapped_column(Boolean, nullable=False, default=True)
+    icon: Mapped[Optional[str]] = mapped_column(String(30), nullable=True)
     created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False, server_default=func.now())
     updated_at: Mapped[datetime] = mapped_column(
         DateTime(timezone=True), nullable=False, server_default=func.now(), onupdate=func.now()