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/scripts/seed_billing_plans.py

@@ -0,0 +1,112 @@
+"""
+种子数据：初始化 3 个默认付费套餐
+用法: cd backend && ./venv/Scripts/python.exe scripts/seed_billing_plans.py
+"""
+import sys
+import os
+sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+
+from app.core.database import SessionLocal, init_db
+from app.models.billing import BillingPlan
+import uuid
+
+PLANS = [
+    {
+        "id": "a0000000-0000-0000-0000-000000000001",
+        "name": "免费版",
+        "tier": "free",
+        "price_monthly": 0,
+        "price_yearly": 0,
+        "daily_quota": 50,
+        "agent_limit": 3,
+        "knowledge_limit": 10,
+        "file_upload_mb": 5,
+        "models": ["deepseek-v4-pro"],
+        "features": [
+            "每日 50 次对话",
+            "3 个自建智能体",
+            "基础模型 DeepSeek-V3",
+            "10 条全局知识",
+            "5 MB 文件上传",
+            "社区支持",
+        ],
+        "is_active": True,
+        "sort_order": 0,
+    },
+    {
+        "id": "a0000000-0000-0000-0000-000000000002",
+        "name": "专业版",
+        "tier": "pro",
+        "price_monthly": 29,
+        "price_yearly": 198,
+        "daily_quota": 500,
+        "agent_limit": 20,
+        "knowledge_limit": 500,
+        "file_upload_mb": 50,
+        "models": ["deepseek-v4-pro", "gpt-4o", "claude-sonnet-4-6", "gemini-2.5-pro"],
+        "features": [
+            "每日 500 次对话",
+            "20 个自建智能体",
+            "全部高级模型",
+            "500 条全局知识",
+            "50 MB 文件上传",
+            "优先响应队列",
+            "对话历史云端同步",
+            "对话导出 Markdown/PDF",
+            "专属客服通道",
+        ],
+        "is_active": True,
+        "sort_order": 1,
+    },
+    {
+        "id": "a0000000-0000-0000-0000-000000000003",
+        "name": "企业版",
+        "tier": "enterprise",
+        "price_monthly": 99,
+        "price_yearly": 899,
+        "daily_quota": 0,
+        "agent_limit": 0,
+        "knowledge_limit": 0,
+        "file_upload_mb": 200,
+        "models": ["deepseek-v4-pro", "gpt-4o", "claude-sonnet-4-6", "gemini-2.5-pro"],
+        "features": [
+            "无限对话次数",
+            "无限智能体",
+            "团队协作（10 人）",
+            "全部知识库功能",
+            "200 MB 文件上传",
+            "最高优先响应",
+            "API 调用额度 ¥50/月",
+            "管理员面板",
+            "专属成功经理 + 电话支持",
+        ],
+        "is_active": True,
+        "sort_order": 2,
+    },
+]
+
+
+def seed():
+    init_db()
+    db = SessionLocal()
+    try:
+        for plan_data in PLANS:
+            existing = db.query(BillingPlan).filter(BillingPlan.id == plan_data["id"]).first()
+            if existing:
+                print(f"跳过已存在: {plan_data['name']}")
+                continue
+            plan = BillingPlan(**plan_data)
+            db.add(plan)
+            print(f"创建套餐: {plan_data['name']} (tier={plan_data['tier']})")
+        db.commit()
+        print("种子数据初始化完成")
+    except Exception as e:
+        db.rollback()
+        print(f"错误: {e}")
+        raise
+    finally:
+        db.close()
+
+
+if __name__ == "__main__":
+    seed()