feat: multi-tenant workspace isolation, RBAC, sidebar nav, billing, and Android enhancements

- Backend: workspace_id isolation for 14 model tables + safe migration/backfill
- Backend: RBAC system with 4 roles and 23 permissions, seeded on startup
- Backend: workspace admin endpoints (list/manage all workspaces)
- Backend: admin user management API (CRUD, reset password)
- Backend: billing API with subscription plans, usage tracking, rate limiting
- Backend: fix system_logs.py UNION query and wrong column references
- Backend: WebSocket JWT auth and workspace enforcement
- Frontend: sidebar navigation replacing top dropdown menu
- Frontend: user management page (Users.vue) for admins
- Frontend: enhanced Workspaces.vue with admin table view
- Frontend: workspace RBAC computed properties in user store
- Android: agent marketplace, billing/subscription UI, onboarding wizard
- Android: phone login, analytics tracker, crash handler, network diagnostics
- Android: splash screen, encrypted token storage, app update enhancements
- Docs: multi-tenant RBAC guide with 8 sections and role-permission matrix

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/app/models/workflow_template.py

@@ -51,6 +51,7 @@ class TemplateRating(Base):
     id = Column(CHAR(36), primary_key=True, default=lambda: str(uuid.uuid4()), comment="评分ID")
     template_id = Column(CHAR(36), ForeignKey("workflow_templates.id"), nullable=False, comment="模板ID")
     user_id = Column(CHAR(36), ForeignKey("users.id"), nullable=False, comment="用户ID")
+    workspace_id = Column(CHAR(36), ForeignKey("workspaces.id"), nullable=True, index=True, comment="工作区ID")
     rating = Column(Integer, nullable=False, comment="评分: 1-5")
     comment = Column(Text, comment="评论")
     created_at = Column(DateTime, default=func.now(), comment="创建时间")
@@ -71,6 +72,7 @@ class TemplateFavorite(Base):
     id = Column(CHAR(36), primary_key=True, default=lambda: str(uuid.uuid4()), comment="收藏ID")
     template_id = Column(CHAR(36), ForeignKey("workflow_templates.id"), nullable=False, comment="模板ID")
     user_id = Column(CHAR(36), ForeignKey("users.id"), nullable=False, comment="用户ID")
+    workspace_id = Column(CHAR(36), ForeignKey("workspaces.id"), nullable=True, index=True, comment="工作区ID")
     created_at = Column(DateTime, default=func.now(), comment="创建时间")
 
     # 关系