feat: add role-based access control and user article management

- Add AdminRequired middleware to all /admin routes for proper authorization
- Restrict admin panel, comments, users, settings to admin role only
- Create separate /my/articles routes for regular users to manage their own articles
- Add MyArticlesPage handler for users to view/edit/delete their own content
- Update navigation menus with role-based visibility
- Admin dropdown shows only 'Admin Panel' link, other features in dashboard
- Regular users see 'My Articles' link in profile dropdown
- Add i18n translations for 'my_articles' and 'comment_manage' keys
- Fix permission boundary issues where author role could access admin settings

Security improvements:
- Platform settings now require admin role
- Comment moderation requires admin role
- User management requires admin role
- Regular users can only manage their own articles

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

i18n/i18n.go

@@ -72,6 +72,7 @@ var translations = map[Lang]map[string]string{
 		// Profile dropdown & page
 		"profile":                "Profile",
 		"admin_panel":            "Admin Panel",
+		"my_articles":            "My Articles",
 		"profile_title":          "Edit Profile",
 		"profile_avatar":         "Avatar",
 		"profile_change_avatar":  "Change Avatar",
@@ -102,17 +103,28 @@ var translations = map[Lang]map[string]string{
 
 		// Article creation
 		"article_create_title": "Create Article",
+		"article_field_title":        "Title",
 		"article_title":        "Title",
+		"article_field_slug":         "Slug",
 		"article_slug":         "Slug",
 		"article_slug_hint":    "Auto-generated from title if empty",
+		"article_slug_help":    "Auto-generated from title if empty",
+		"article_field_summary":      "Summary",
 		"article_summary":      "Summary",
+		"article_field_content":      "Content",
 		"article_content":      "Content",
+		"article_field_cover":        "Cover Image URL",
 		"article_cover":        "Cover Image URL",
+		"article_cover_help":   "Optional cover image URL",
+		"article_field_status":       "Status",
 		"article_status":       "Status",
 		"article_draft":        "Draft",
 		"article_published":    "Published",
+		"article_field_is_top":       "Pin to top",
 		"article_is_top":       "Pin to top",
 		"article_save_draft":   "Save Draft",
+		"article_save":         "Save",
+		"article_cancel":       "Cancel",
 		"article_publish":      "Publish",
 		"article_created":      "Article created successfully.",
 		"article_error":        "Failed to create article.",
@@ -135,6 +147,7 @@ var translations = map[Lang]map[string]string{
 
 		// Article management
 		"article_list_title":      "Articles",
+		"my_articles_title":       "My Articles",
 		"article_edit_title":      "Edit Article",
 		"article_manage":          "Manage Articles",
 		"article_edit":            "Edit",
@@ -241,6 +254,7 @@ var translations = map[Lang]map[string]string{
 
 		// Admin: comments
 		"admin_comments":               "Comments",
+		"comment_manage":               "Manage Comments",
 		"admin_comments_title":         "Comments",
 		"comment_status_pending":       "Pending",
 		"comment_status_approved":      "Approved",
@@ -368,6 +382,7 @@ var translations = map[Lang]map[string]string{
 		// 个人中心下拉菜单 & 页面
 		"profile":                "个人信息",
 		"admin_panel":            "后台管理",
+		"my_articles":            "我的文章",
 		"profile_title":          "编辑个人信息",
 		"profile_avatar":         "头像",
 		"profile_change_avatar":  "更换头像",
@@ -398,17 +413,28 @@ var translations = map[Lang]map[string]string{
 
 		// 文章创建
 		"article_create_title": "新建文章",
+		"article_field_title":        "标题",
 		"article_title":        "标题",
+		"article_field_slug":         "Slug",
 		"article_slug":         "Slug",
 		"article_slug_hint":    "留空则从标题自动生成",
+		"article_slug_help":    "留空则从标题自动生成",
+		"article_field_summary":      "摘要",
 		"article_summary":      "摘要",
+		"article_field_content":      "正文",
 		"article_content":      "正文",
+		"article_field_cover":        "封面图 URL",
 		"article_cover":        "封面图 URL",
+		"article_cover_help":   "可选的封面图片链接",
+		"article_field_status":       "状态",
 		"article_status":       "状态",
 		"article_draft":        "草稿",
 		"article_published":    "已发布",
+		"article_field_is_top":       "置顶",
 		"article_is_top":       "置顶",
 		"article_save_draft":   "保存草稿",
+		"article_save":         "保存",
+		"article_cancel":       "取消",
 		"article_publish":      "发布",
 		"article_created":      "文章创建成功。",
 		"article_error":        "创建文章失败。",
@@ -431,6 +457,7 @@ var translations = map[Lang]map[string]string{
 
 		// 文章管理
 		"article_list_title":      "文章管理",
+		"my_articles_title":       "我的文章",
 		"article_edit_title":      "编辑文章",
 		"article_manage":          "文章管理",
 		"article_edit":            "编辑",
@@ -537,6 +564,7 @@ var translations = map[Lang]map[string]string{
 
 		// 后台：评论
 		"admin_comments":               "评论管理",
+		"comment_manage":               "评论管理",
 		"admin_comments_title":         "评论管理",
 		"comment_status_pending":       "待审核",
 		"comment_status_approved":      "已通过",