feat: complete P0-2 Token Refresh, P0-4 Android ProGuard, P0-5 App Update

- P0-2: Refresh token with Redis storage (UUID tokens, 30-day TTL, rotation on refresh)
- P0-2: Backend POST /auth/refresh and /auth/revoke endpoints
- P0-2: Android AuthInterceptor refresh-before-re-login flow
- P0-2: AuthRepository saves refresh_token on login, revokes on logout
- P0-4: Enable R8 minification (isMinifyEnabled=true) with comprehensive keep rules
- P0-5: Backend GET /api/v1/app/check-update with force_update support
- P0-5: Android AppUpdateManager with force/optional update dialogs on startup

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

backend/app/main.py

@@ -510,7 +510,7 @@ async def startup_event():
         logger.error(f"定时任务调度器启动失败: {e}")
 
 # 注册路由
-from app.api import auth, workspaces, uploads, workflows, executions, websocket, execution_logs, data_sources, agents, platform_templates, model_configs, webhooks, template_market, batch_operations, collaboration, permissions, monitoring, alert_rules, node_test, node_templates, tools, agent_chat, agent_branches, agent_monitoring, knowledge_base, knowledge_dashboard, agent_schedules, notifications, feishu_bind, approval, orchestration_templates, plugins, agent_market, goals, tasks, system_logs, audit_logs, feedback, agent_swarm, push, voice, fcm, scene_contracts, teams, agent_memory, legal
+from app.api import auth, workspaces, uploads, workflows, executions, websocket, execution_logs, data_sources, agents, platform_templates, model_configs, webhooks, template_market, batch_operations, collaboration, permissions, monitoring, alert_rules, node_test, node_templates, tools, agent_chat, agent_branches, agent_monitoring, knowledge_base, knowledge_dashboard, agent_schedules, notifications, feishu_bind, approval, orchestration_templates, plugins, agent_market, goals, tasks, system_logs, audit_logs, feedback, agent_swarm, push, voice, fcm, scene_contracts, teams, agent_memory, legal, app_update
 
 app.include_router(auth.router)
 app.include_router(workspaces.router)
@@ -558,6 +558,7 @@ app.include_router(scene_contracts.router)
 app.include_router(teams.router)
 app.include_router(agent_memory.router)
 app.include_router(legal.router)
+app.include_router(app_update.router)
 
 if __name__ == "__main__":
     import uvicorn