refactor(repo): replace legacy openflare-server with Wavelet rename

Delete the old monolithic openflare-server implementation and rename
Wavelet/ to openflare-server/ to complete the migration consolidation.
Update CI workflows, agent Dockerfiles, and deployment docs for the new
layout (frontend/, docker/Dockerfile).

openflare-server/frontend/lib/theme/parser.ts

@@ -0,0 +1,11 @@
+import type {Theme} from "./types"
+import themesData from "./themes.json"
+
+/**
+ * 获取所有可用主题
+ * 从预生成的 themes.json 中直接读取主题列表和颜色配置
+ * @returns 主题列表，已按默认主题优先且其余按名称排序
+ */
+export async function getAvailableThemes(): Promise<Theme[]> {
+  return themesData as Theme[];
+}