feat(server): implement chat file TTL cleanup and enhance JPush vendor channel support

Add FileCleanupWorker for automatic expiration of chat files with configurable retention period and batch processing. Files uploaded via `/api/v1/uploads/files` are tracked in `uploaded_files` table with expiration timestamps, then deleted from S3 and database upon expiry. Expired file URLs are injected as `"expired": true` in message responses.

Extend JPush push notification configuration with vendor-specific channel_id support (xiaomi, huawei, oppo, vivo, meizu, honor, fcm) for differentiating system vs chat notifications. Add iOS APNs thread-id grouping configuration for notification categorization.

internal/config/jpush.go

@@ -1,8 +1,63 @@
 package config
 
 type JPushConfig struct {
-	Enabled     bool   `mapstructure:"enabled"`
-	AppKey      string `mapstructure:"app_key"`
-	MasterSecret string `mapstructure:"master_secret"`
-	Production  bool   `mapstructure:"production"`
-}
+	Enabled      bool          `mapstructure:"enabled"`
+	AppKey       string        `mapstructure:"app_key"`
+	MasterSecret string        `mapstructure:"master_secret"`
+	Production   bool          `mapstructure:"production"`
+	// Channel 厂商通道 channel_id 配置
+	// 通过 options.third_party_channel 下发到各厂商（小米/华为/OPPO 等）
+	Channel ChannelConfig `mapstructure:"channel"`
+}
+
+// ChannelConfig 厂商通道 channel_id 配置
+// 区分「系统消息」与「私聊/群聊消息」两类 channel
+type ChannelConfig struct {
+	// System 系统消息/通知默认 channel_id，未单独配置 Vendor 时各厂商共用
+	System string `mapstructure:"system"`
+	// Chat 私聊/群聊消息默认 channel_id，未单独配置 Vendor 时各厂商共用
+	Chat string `mapstructure:"chat"`
+	// Vendor 各厂商 channel_id 覆盖配置（留空则回退到 System/Chat）
+	Vendor VendorChannel `mapstructure:"vendor"`
+	// iOS APNs 通知场景区分配置（按 thread-id 分组）
+	IOS IOSChannelConfig `mapstructure:"ios"`
+}
+
+// IOSChannelConfig iOS APNs 通知场景区分配置
+// iOS 走 APNs 无 channel_id 概念，通过 thread-id 实现通知分组
+type IOSChannelConfig struct {
+	// ChatThreadID 私聊/群聊消息通知分组 thread-id
+	ChatThreadID string `mapstructure:"chat_thread_id"`
+	// SystemThreadID 系统消息/通知分组 thread-id
+	SystemThreadID string `mapstructure:"system_thread_id"`
+}
+
+// VendorChannel 各厂商通道 channel_id 覆盖
+// 每个厂商区分 System（系统消息）与 Chat（私聊消息）两个 channel_id
+type VendorChannel struct {
+	Xiaomi VendorChannelID `mapstructure:"xiaomi"`
+	Huawei VendorChannelID `mapstructure:"huawei"`
+	OPPO   VendorChannelID `mapstructure:"oppo"`
+	VIVO   VendorChannelID `mapstructure:"vivo"`
+	Meizu  VendorChannelID `mapstructure:"meizu"`
+	Honor  VendorChannelID `mapstructure:"honor"`
+	FCM    VendorChannelID `mapstructure:"fcm"`
+}
+
+// VendorChannelID 单个厂商的两类 channel 配置
+// 每个 channel 可携带厂商私有模板配置（如小米 mi_template_id、OPPO private_msg_template_id）
+type VendorChannelID struct {
+	// channel_id
+	System string `mapstructure:"system"`
+	Chat   string `mapstructure:"chat"`
+
+	// 小米消息模板（可选，配置后私信消息下发时携带 channel_id 及 mi_template_id）
+	// 见：小米关于消息模板推送新规的更新通知
+	MiSystemTemplateID string `mapstructure:"mi_system_template_id"` // 系统消息模板 id
+	MiChatTemplateID   string `mapstructure:"mi_chat_template_id"`   // 私聊消息模板 id
+
+	// OPPO 私信模板（可选，仅 OPPO 厂商，配置后下发私信时携带）
+	// 见：OPUSH 私信模版校验能力接入说明
+	OppoSystemPrivateTemplateID string `mapstructure:"oppo_system_private_template_id"` // 系统消息私信模板 id
+	OppoChatPrivateTemplateID   string `mapstructure:"oppo_chat_private_template_id"`   // 私聊消息私信模板 id
+}