refactor(repo): consolidate openflare-server to root and move subprojects to internal/apps

- Merge all files inside openflare-server to the repository root directory.
- Relocate agent, relay, and flared subprojects from internal/ to internal/apps/.
- Combine docker-compose files and update build context paths to root.
- Update GitHub workflows and Dockerfiles to refer to new directories and package names.
- Rewrite Go package imports across all files.
- Resolve database renew test race condition and clean up docs.

internal/model/push_history.go

@@ -0,0 +1,27 @@
+// Copyright 2026 Arctel.net
+// SPDX-License-Identifier: Apache-2.0
+
+package model
+
+import (
+	"time"
+)
+
+// PushHistory 推送日志/历史实体
+type PushHistory struct {
+	ID        uint64    `json:"id" gorm:"primaryKey;autoIncrement"`
+	EventKey  string    `json:"event_key" gorm:"size:80;not null;index"`
+	Channel   string    `json:"channel" gorm:"size:50;not null"`
+	Target    string    `json:"target" gorm:"size:255;not null"`
+	Title     string    `json:"title" gorm:"size:255;not null"`
+	Content   string    `json:"content" gorm:"type:text;not null"`
+	Level     string    `json:"level" gorm:"size:20;not null"`
+	Status    string    `json:"status" gorm:"size:20;not null"` // success / failed
+	ErrorMsg  string    `json:"error_msg" gorm:"type:text"`
+	CreatedAt time.Time `json:"created_at" gorm:"autoCreateTime;index"`
+}
+
+// TableName 指定表名
+func (PushHistory) TableName() string {
+	return "w_push_histories"
+}