docs(comments): 注释中文化 · plugins/channels/weixin_ilink（20 文件，纯替换）

- 只翻注释/文档字符串：剥掉行尾注释后，每条「-」都有逐字节相同的「+」对应行（8 组，代码零改动）
- 保留协议/线上标识符原文：errcode、bot_token、context_token、getupdates、binded_redirect、PKCS#7、ECB 等
- 术语对齐既有译法：owner→主人、peer→对端、long poll→长轮询、backoff→退避、sentinel error→哨兵错误
- 已知既有欠债（未顺手修）：login_reuse_test.go 在 HEAD 上就未 gofmt 干净；login_test.go 的 TestStartLogin_ScanStatusTransition 91 行 >80（HEAD 同为 91 行）

plugins/channels/weixin_ilink/media.go

@@ -11,15 +11,12 @@ import (
 	"strings"
 )
 
-// ErrKeyTooShort is returned when the inbound derivation cannot yield an AES
-// key of the required block size.
+// ErrKeyTooShort 在入站密钥推导无法给出所需分组长度的 AES 密钥时返回。
 var ErrKeyTooShort = errors.New("weixin_ilink: derived key shorter than a block")
 
-// deriveInboundKey derives the AES-128 key for an inbound media payload. Per
-// design/08 §3.3 the key is extracted from the bot_token: base64-decode the
-// token and take the trailing 16 bytes. This is marked ⚠️ in the reference, so
-// DownloadMediaWithKey lets callers supply an explicit key when the platform
-// carries one per item instead.
+// deriveInboundKey 为入站媒体负载推导 AES-128 密钥。按 design/08 §3.3，密钥从
+// bot_token 中提取：先 base64 解码 token，再取末尾 16 字节。参考实现把这一步标记为
+// ⚠️，因此 DownloadMediaWithKey 允许调用方在平台按每条媒体下发密钥时显式传入密钥。
 func deriveInboundKey(botToken string) ([]byte, error) {
 	token := strings.TrimSpace(botToken)
 	if token == "" {
@@ -35,9 +32,8 @@ func deriveInboundKey(botToken string) ([]byte, error) {
 	return b[len(b)-aes.BlockSize:], nil
 }
 
-// DownloadMedia downloads an inbound CDN reference and returns the decrypted
-// plaintext using the key derived from the configured bot_token. It fails with
-// ErrMediaTooLarge when the ciphertext exceeds MaxMediaSize.
+// DownloadMedia 下载一条入站 CDN 引用，并用从已配置 bot_token 推导出的密钥返回
+// 明文。密文超过 MaxMediaSize 时以 ErrMediaTooLarge 失败。
 func (a *Adapter) DownloadMedia(ctx context.Context, cdnURL string) ([]byte, error) {
 	key, err := deriveInboundKey(a.cfg.BotToken)
 	if err != nil {
@@ -46,8 +42,8 @@ func (a *Adapter) DownloadMedia(ctx context.Context, cdnURL string) ([]byte, err
 	return a.downloadWithKey(ctx, cdnURL, key)
 }
 
-// DownloadMediaWithKey is DownloadMedia with an explicit per-item AES key,
-// used when the protocol delivers the key alongside the media reference.
+// DownloadMediaWithKey 是 DownloadMedia 的显式按条 AES 密钥版本，用于协议把密钥
+// 与媒体引用一并下发的场景。
 func (a *Adapter) DownloadMediaWithKey(ctx context.Context, cdnURL string, key []byte) ([]byte, error) {
 	if len(key) != aes.BlockSize {
 		return nil, fmt.Errorf("weixin_ilink: key must be %d bytes: %w", aes.BlockSize, ErrKeyTooShort)
@@ -55,7 +51,7 @@ func (a *Adapter) DownloadMediaWithKey(ctx context.Context, cdnURL string, key [
 	return a.downloadWithKey(ctx, cdnURL, key)
 }
 
-// downloadWithKey fetches the CDN bytes and removes the AES-ECB layer.
+// downloadWithKey 拉取 CDN 字节并剥掉 AES-ECB 层。
 func (a *Adapter) downloadWithKey(ctx context.Context, cdnURL string, key []byte) ([]byte, error) {
 	ciphertext, err := a.fetchBody(ctx, a.cdnURL(cdnURL))
 	if err != nil {
@@ -68,8 +64,8 @@ func (a *Adapter) downloadWithKey(ctx context.Context, cdnURL string, key []byte
 	return plaintext, nil
 }
 
-// fetchBody GETs rawURL and returns the body, refusing anything over
-// MaxMediaSize so a single huge file cannot exhaust memory.
+// fetchBody 对 rawURL 发 GET 并返回响应体，超过 MaxMediaSize 的一律拒绝，避免单个
+// 超大文件耗尽内存。
 func (a *Adapter) fetchBody(ctx context.Context, rawURL string) ([]byte, error) {
 	req, err := http.NewRequestWithContext(ctx, http.MethodGet, rawURL, nil)
 	if err != nil {