refactor: 拆分 admin handler 大文件为模块目录，消除 shared.rs 反模式

- endpoint_keys/pool/architecture 等大文件拆分为独立模块目录
- 删除 crud/query/strategy/system 中的 shared.rs，内容归位到各自模块
- endpoints_admin/models/oauth/write 等模块拆出 payloads/responses/support 子文件
- system/core 下多个 *_routes.rs 合并到 system_routes.rs
- 更新 refactor-execution-plan 文档进度

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

@@ -1,5 +1,4 @@
+mod responses;
 mod routes;
-mod shared;
 
 pub(crate) use routes::maybe_build_local_admin_providers_response;
-use shared::*;

apps/aether-gateway/src/handlers/admin/provider/crud/routes.rs

@@ -1,26 +1,30 @@
-use super::shared::build_admin_providers_data_unavailable_response;
+use super::responses::build_admin_providers_data_unavailable_response;
 use crate::control::GatewayPublicRequestContext;
 use crate::handlers::admin::provider::delete_task::{
     build_admin_provider_mapping_preview_payload, run_admin_provider_delete_task,
 };
-use crate::handlers::admin::provider::pool::{
+use crate::handlers::admin::provider::pool::runtime::{
     build_admin_provider_pool_status_payload, clear_admin_provider_pool_cooldown,
     reset_admin_provider_pool_cost,
 };
-use crate::handlers::admin::provider::shared::{
+use crate::handlers::admin::provider::shared::paths::{
     admin_provider_clear_pool_cooldown_parts, admin_provider_delete_task_parts,
     admin_provider_id_for_health_monitor, admin_provider_id_for_manage_path,
     admin_provider_id_for_mapping_preview, admin_provider_id_for_pool_status,
-    admin_provider_id_for_summary, admin_provider_reset_pool_cost_parts,
-    build_admin_provider_delete_task_payload, is_admin_providers_root,
-    put_admin_provider_delete_task, AdminProviderCreateRequest, AdminProviderUpdateRequest,
+    admin_provider_id_for_summary, admin_provider_reset_pool_cost_parts, is_admin_providers_root,
+};
+use crate::handlers::admin::provider::shared::payloads::{
+    AdminProviderCreateRequest, AdminProviderUpdateRequest,
+};
+use crate::handlers::admin::provider::shared::support::{
+    build_admin_provider_delete_task_payload, put_admin_provider_delete_task,
 };
 use crate::handlers::admin::provider::summary::{
     build_admin_provider_health_monitor_payload, build_admin_provider_summary_payload,
     build_admin_provider_summary_value, build_admin_providers_payload,
     build_admin_providers_summary_payload,
 };
-use crate::handlers::admin::provider::write::{
+use crate::handlers::admin::provider::write::provider::{
     build_admin_create_provider_record, build_admin_fixed_provider_endpoint_record,
     build_admin_update_provider_record,
 };