refactor: 移除 Python upstream 依赖，清理全部 legacy/Python 兼容层

- 移除 upstream_base_url 参数及 AETHER_GATEWAY_UPSTREAM 环境变量，gateway 不再需要指向 Python 宿主
- 删除所有 LEGACY_*/PYTHON_* 常量、路由组、header 定义及 sunset/phaseout 机制
- 将 legacy_gateway_bridge 重命名为 internal_gateway，executor 相关命名统一为 execution_runtime
- dev.sh 新增 Postgres/Redis 预检查，移除 upstream 相关启动参数和提示
- 新增 ai_public 路由处理器
- 全量适配 handler、test、state、control 等模块的命名和接口变更

apps/aether-gateway/src/handlers/admin/mod.rs

@@ -1,4 +1,8 @@
-pub(crate) use super::*;
+use super::{
+    admin_clear_oauth_invalid_key_id, admin_export_key_id, admin_provider_id_for_refresh_quota,
+    admin_reveal_key_id, admin_update_key_id, build_admin_provider_key_response,
+    INTERNAL_GATEWAY_PATH_PREFIXES,
+};
 
 mod adaptive;
 mod api_keys;
@@ -38,37 +42,69 @@ mod users;
 mod video_tasks;
 mod wallets;
 
-pub(crate) use self::adaptive::*;
-pub(crate) use self::api_keys::*;
-pub(crate) use self::billing::*;
-pub(crate) use self::catalog_write_helpers::*;
-pub(crate) use self::core::*;
-pub(crate) use self::endpoints::*;
-pub(crate) use self::endpoints_health_helpers::*;
-pub(crate) use self::gemini_files::*;
-pub(crate) use self::global_models::*;
-pub(crate) use self::ldap::*;
-pub(crate) use self::misc_helpers::*;
-pub(crate) use self::models_helpers::*;
+pub(crate) use self::adaptive::maybe_build_local_admin_adaptive_response;
+use self::adaptive::*;
+pub(crate) use self::api_keys::maybe_build_local_admin_api_keys_response;
+use self::api_keys::*;
+pub(crate) use self::billing::maybe_build_local_admin_billing_response;
+use self::billing::*;
+use self::catalog_write_helpers::*;
+pub(crate) use self::core::maybe_build_local_admin_core_response;
+use self::core::*;
+pub(crate) use self::endpoints::maybe_build_local_admin_endpoints_response;
+use self::endpoints::*;
+pub(crate) use self::endpoints_health_helpers::build_admin_endpoint_health_status_payload;
+use self::endpoints_health_helpers::*;
+pub(crate) use self::gemini_files::maybe_build_local_admin_gemini_files_response;
+use self::gemini_files::*;
+pub(crate) use self::global_models::maybe_build_local_admin_global_models_response;
+use self::global_models::*;
+pub(crate) use self::ldap::maybe_build_local_admin_ldap_response;
+use self::ldap::*;
+use self::misc_helpers::*;
+pub(crate) use self::misc_helpers::{
+    build_admin_proxy_auth_required_response, build_unhandled_admin_proxy_response,
+    provider_catalog_key_supports_format,
+};
+use self::models_helpers::*;
 pub(crate) use self::monitoring::maybe_build_local_admin_monitoring_root_response as maybe_build_local_admin_monitoring_response;
-pub(crate) use self::oauth_helpers::*;
-pub(crate) use self::payments::*;
-pub(crate) use self::pool::*;
-pub(crate) use self::provider_models::*;
-pub(crate) use self::provider_oauth_dispatch::*;
-pub(crate) use self::provider_oauth_quota::*;
-pub(crate) use self::provider_oauth_refresh::*;
-pub(crate) use self::provider_oauth_state::*;
+use self::oauth_helpers::*;
+pub(crate) use self::payments::maybe_build_local_admin_payments_response;
+use self::payments::*;
+pub(crate) use self::pool::maybe_build_local_admin_pool_response;
+use self::pool::*;
+pub(crate) use self::provider_models::maybe_build_local_admin_provider_models_response;
+use self::provider_models::*;
+pub(crate) use self::provider_oauth_dispatch::maybe_build_local_admin_provider_oauth_response;
+use self::provider_oauth_dispatch::*;
+use self::provider_oauth_quota::*;
+pub(crate) use self::provider_oauth_refresh::build_internal_control_error_response;
+use self::provider_oauth_refresh::*;
+use self::provider_oauth_state::*;
 pub(crate) use self::provider_ops::admin_provider_ops_local_action_response;
 pub(crate) use self::provider_ops::maybe_build_local_admin_provider_ops_response;
-pub(crate) use self::provider_query::*;
-pub(crate) use self::provider_strategy::*;
-pub(crate) use self::providers::*;
-pub(crate) use self::providers_helpers::*;
-pub(crate) use self::proxy_nodes::*;
-pub(crate) use self::security::*;
-pub(crate) use self::stats::*;
-pub(crate) use self::usage::*;
-pub(crate) use self::users::*;
-pub(crate) use self::video_tasks::*;
-pub(crate) use self::wallets::*;
+pub(crate) use self::provider_query::maybe_build_local_admin_provider_query_response;
+use self::provider_query::*;
+pub(crate) use self::provider_strategy::maybe_build_local_admin_provider_strategy_response;
+use self::provider_strategy::*;
+pub(crate) use self::providers::maybe_build_local_admin_providers_response;
+use self::providers::*;
+use self::providers_helpers::*;
+pub(crate) use self::proxy_nodes::maybe_build_local_admin_proxy_nodes_response;
+use self::proxy_nodes::*;
+pub(crate) use self::security::maybe_build_local_admin_security_response;
+use self::security::*;
+use self::stats::*;
+pub(crate) use self::stats::{
+    admin_stats_bad_request_response, list_usage_for_optional_range,
+    maybe_build_local_admin_stats_response, parse_bounded_u32, round_to, AdminStatsTimeRange,
+    AdminStatsUsageFilter,
+};
+pub(crate) use self::usage::maybe_build_local_admin_usage_response;
+use self::usage::*;
+pub(crate) use self::users::maybe_build_local_admin_users_response;
+use self::users::*;
+pub(crate) use self::video_tasks::maybe_build_local_admin_video_tasks_response;
+use self::video_tasks::*;
+pub(crate) use self::wallets::maybe_build_local_admin_wallets_response;
+use self::wallets::*;