refactor: 移除 LiteLLM proxy 架构，后端直连 Provider API

- 移除 backend/scripts/build_litellm_proxy_config.py
- 简化 LiteLLMService，移除 run_completion_with_cost 方法
- AgentScopeRunner 改为从 LlmFactory 获取 api_base 和 api_key
- 部署配置移除 litellm/litellm-config-job 服务
- Flutter 新增 AuthBootScreen 引导页
- Android 添加通知权限 (POST_NOTIFICATIONS, RECEIVE_BOOT_COMPLETED, SCHEDULE_EXACT_ALARM)
- 优化 LocalNotificationService 调度失败 fallback
- 更新 manifest.json (version 3)

infra/scripts/app.sh

@@ -116,7 +116,7 @@ kill_listening_processes() {
 start() {
   echo "=== App Up ==="
   echo "This script starts local web + worker processes in tmux."
-  echo "LiteLLM/Redis should be managed separately as long-running docker services."
+  echo "Redis should be managed separately as a long-running docker service."
   echo "NOTE: Bootstrap (migrate + init-data) must be run separately."
   echo ""
 
@@ -184,7 +184,7 @@ ${SOCIAL_WEB__WORKERS:-2} --log-level ${UVICORN_LOG_LEVEL}"
 
 stop() {
   echo "=== App Down ==="
-  echo "Stopping tmux app processes (docker redis/litellm are not managed here)."
+  echo "Stopping tmux app processes (docker redis is not managed here)."
   load_env_if_exists
   WEB_PORT="${SOCIAL_WEB__PORT:-5775}"