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/endpoints/keys.rs

@@ -1,9 +1,33 @@
-pub(crate) use super::*;
+use super::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_create_provider_key_record,
+    build_admin_export_key_payload, build_admin_provider_key_response,
+    build_admin_provider_keys_payload, build_admin_reveal_key_payload,
+    build_admin_update_provider_key_record, normalize_string_id_list,
+    refresh_antigravity_provider_quota_locally, refresh_codex_provider_quota_locally,
+    refresh_kiro_provider_quota_locally,
+};
+use crate::gateway::handlers::public::build_admin_keys_grouped_by_format_payload;
+use crate::gateway::handlers::{
+    admin_provider_id_for_keys, query_param_value, AdminProviderKeyBatchDeleteRequest,
+    AdminProviderKeyCreateRequest, AdminProviderKeyUpdateRequest, AdminProviderQuotaRefreshRequest,
+    OAUTH_ACCOUNT_BLOCK_PREFIX,
+};
+use crate::gateway::{AppState, GatewayError, GatewayPublicRequestContext};
+use axum::{
+    body::{Body, Bytes},
+    http,
+    response::{IntoResponse, Response},
+    Json,
+};
+use serde_json::json;
+use std::collections::BTreeSet;
+use std::time::{SystemTime, UNIX_EPOCH};
 
 pub(super) async fn maybe_build_local_admin_endpoints_keys_response(
     state: &AppState,
     request_context: &GatewayPublicRequestContext,
-    request_body: Option<&axum::body::Bytes>,
+    request_body: Option<&Bytes>,
 ) -> Result<Option<Response<Body>>, GatewayError> {
     let Some(decision) = request_context.control_decision.as_ref() else {
         return Ok(None);