新增 OIDC/SSO、邮件验证码与 Gitea 项目同步，并强化 Feed 与管理后台。

作为 OIDC Provider 对接 Gitea；注册支持邮件验证码/验证码；侧栏同步公开仓库；Feed 分页、文章大纲、标签云与站点品牌设置。

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/src/utils/composeDraft.ts

@@ -0,0 +1,61 @@
+export interface ComposeDraft {
+  title: string;
+  tags: string;
+  content: string;
+  boardId: string;
+  savedAt: number;
+}
+
+const PREFIX = 'j13-compose-draft:';
+
+function draftKey(editId: number | null): string {
+  return editId == null ? `${PREFIX}new` : `${PREFIX}edit:${editId}`;
+}
+
+/** 读取发帖/编辑草稿 */
+export function loadComposeDraft(editId: number | null): ComposeDraft | null {
+  try {
+    const raw = localStorage.getItem(draftKey(editId));
+    if (!raw) return null;
+    const data = JSON.parse(raw) as ComposeDraft;
+    if (!data || typeof data !== 'object') return null;
+    return {
+      title: typeof data.title === 'string' ? data.title : '',
+      tags: typeof data.tags === 'string' ? data.tags : '',
+      content: typeof data.content === 'string' ? data.content : '',
+      boardId: typeof data.boardId === 'string' ? data.boardId : '',
+      savedAt: typeof data.savedAt === 'number' ? data.savedAt : 0,
+    };
+  } catch {
+    return null;
+  }
+}
+
+/** 写入发帖/编辑草稿 */
+export function saveComposeDraft(editId: number | null, draft: Omit<ComposeDraft, 'savedAt'>): void {
+  try {
+    const payload: ComposeDraft = { ...draft, savedAt: Date.now() };
+    localStorage.setItem(draftKey(editId), JSON.stringify(payload));
+  } catch {
+    // 配额不足等场景静默忽略
+  }
+}
+
+/** 清除发帖/编辑草稿 */
+export function clearComposeDraft(editId: number | null): void {
+  try {
+    localStorage.removeItem(draftKey(editId));
+  } catch {
+    // ignore
+  }
+}
+
+/** 草稿是否相对 baseline 有实质内容 */
+export function draftHasContent(draft: ComposeDraft): boolean {
+  return Boolean(
+    draft.title.trim()
+    || draft.tags.trim()
+    || draft.content.trim()
+    || draft.boardId.trim(),
+  );
+}