feat: implement comprehensive blog system

Add dual-source blog system with Editor.js integration:
- Blog storage supporting repo-based (JSON) and database sources
- Admin panel with rich text editor using Editor.js
- Public news page with infinite scroll
- Individual blog post viewer page
- Categories management in admin
- Image upload functionality
- 4 SEO blog posts about WordPress with PluginCompass promotion
- 3 News blog posts about Plugin Compass
- API endpoints for CRUD operations
- Security and validation for admin operations

Closes blog feature request

chat/blogs/README.md

@@ -0,0 +1,56 @@
+# Blog System
+
+This directory contains blog posts stored as JSON files.
+
+## Structure
+
+```
+blogs/
+├── news/           # News blog posts (displayed on /news page)
+└── seo/            # SEO blog posts (accessible via direct URL only)
+```
+
+## Blog Post Format
+
+```json
+{
+  "id": "unique-slug",
+  "type": "news" | "seo",
+  "title": "Post Title",
+  "slug": "url-friendly-slug",
+  "content": {
+    "blocks": [
+      {
+        "type": "header",
+        "data": {
+          "text": "Heading",
+          "level": 2
+        }
+      },
+      {
+        "type": "paragraph",
+        "data": {
+          "text": "Content here..."
+        }
+      }
+    ]
+  },
+  "excerpt": "Short description",
+  "author": "Author Name",
+  "status": "published",
+  "featured_image": "/blogs/images/filename.jpg",
+  "meta_title": "SEO Title",
+  "meta_description": "SEO Description",
+  "category": "Category Name",
+  "tags": ["tag1", "tag2"],
+  "published_at": "2026-01-15T10:00:00Z",
+  "updated_at": "2026-01-15T10:00:00Z"
+}
+```
+
+## Notes
+
+- Files in this directory are read-only in the admin panel
+- To edit repo-based blogs, modify the JSON files directly
+- Host-created blogs are stored in the database and editable via admin panel
+- Images should be placed in `/public/blogs/images/`