收口微信领域能力

将 api-server 微信 HTTP/BFF 适配统一迁移到 wechat 目录。

将微信支付和虚拟支付消息协议细节下沉到 platform-wechat。

拆分 platform-wechat 的订阅消息与支付模块并补齐依赖。

修正微信相关测试的用户 ID 夹具并同步后端架构文档。

server-rs/crates/api-server/src/state.rs

@@ -27,7 +27,7 @@ use platform_auth::{
 };
 use platform_llm::{LlmClient, LlmConfig, LlmError, LlmProvider};
 use platform_oss::{OssClient, OssConfig, OssError};
-use platform_wechat::{WechatClient, WechatConfig};
+use platform_wechat::{WechatClient, WechatConfig, pay::WechatPayClient};
 use serde_json::Value;
 use shared_contracts::creation_entry_config::CreationEntryConfigResponse;
 use shared_contracts::creative_agent::CreativeAgentSessionSnapshot;
@@ -39,8 +39,8 @@ use tracing::{info, warn};
 use crate::config::AppConfig;
 use crate::puzzle_gallery_cache::PuzzleGalleryCache;
 use crate::tracking_outbox::TrackingOutbox;
-use crate::wechat_pay::{WechatPayClient, map_wechat_pay_init_error};
-use crate::wechat_provider::build_wechat_provider;
+use crate::wechat::pay::{build_wechat_pay_config, map_wechat_pay_init_error};
+use crate::wechat::provider::build_wechat_provider;
 use crate::work_author::{
     ORPHAN_WORK_AUTHOR_DISPLAY_NAME, ORPHAN_WORK_AUTHOR_PUBLIC_USER_CODE, ORPHAN_WORK_OWNER_USER_ID,
 };
@@ -388,8 +388,8 @@ impl AppState {
         let wechat_auth_service = WechatAuthService::new(auth_store.clone());
         let wechat_provider = build_wechat_provider(&config);
         let wechat_client = build_wechat_client(&config);
-        let wechat_pay_client =
-            WechatPayClient::from_config(&config).map_err(map_wechat_pay_init_error)?;
+        let wechat_pay_client = WechatPayClient::from_config(&build_wechat_pay_config(&config))
+            .map_err(map_wechat_pay_init_error)?;
         let refresh_session_service =
             RefreshSessionService::new(auth_store.clone(), config.refresh_session_ttl_days);
         // AI 编排服务当前先挂接内存态 store，后续再按 task table / procedure 接到 SpacetimeDB 真相源。