chore: bump to 1.5.15, publish full package + hot update

- 版本号 1.5.14 → 1.5.15
- 新增 scripts/publish-full.js：一键上传完整包到 latest 与 v<version> release
- 清理未引用的 session_sync_enhanced.js 与临时 test-sync.js

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

package.json

@@ -1,11 +1,11 @@
 {
   "name": "codex-market",
-  "version": "1.5.14",
+  "version": "1.5.15",
   "description": "TD工具箱 / 技能商店 / 备份工具 —— 跨平台桌面客户端",
   "author": "Codex Market",
   "license": "MIT",
   "main": "electron/bootstrap.js",
-  "hotContentVersion": "1.5.14",
+  "hotContentVersion": "1.5.15",
   "scripts": {
     "start": "electron .",
     "dist": "electron-builder",