Implement organized media folder structure for community posts

- Add media_folder field to Post model for organized file storage
- Create MediaConfig class for centralized media management settings
- Update community routes to use post-specific media folders
- Add thumbnail generation for uploaded images
- Implement structured folder layout: app/static/media/posts/{post_folder}/
- Add utility functions for image and GPX file handling
- Create media management script for migration and maintenance
- Add proper file validation and MIME type checking
- Include routes for serving images, thumbnails, and GPX files
- Maintain backward compatibility with existing uploads
- Add comprehensive documentation and migration tools

Each post now gets its own media folder with subfolders for:
- images/ (with thumbnails/ subfolder)
- gpx/

Post content remains in database for optimal query performance while
media files are organized in dedicated folders for better management.

MEDIA_MANAGEMENT.md

@@ -0,0 +1,122 @@
+# Media Management for Motorcycle Adventure Community
+
+## Overview
+
+The application now uses an organized media folder structure where each post has its own dedicated folder for storing images, GPX files, and other media content.
+
+## Folder Structure
+
+```
+app/static/media/posts/
+├── post_abc12345_20250723/
+│   ├── images/
+│   │   ├── cover_image.jpg
+│   │   ├── route_photo_1.jpg
+│   │   └── route_photo_2.jpg
+│   └── gpx/
+│       └── route_track.gpx
+├── post_def67890_20250724/
+│   ├── images/
+│   └── gpx/
+└── ...
+```
+
+## Post Content Storage Strategy
+
+### Database Storage (Recommended ✅)
+- **Post metadata**: title, subtitle, content, difficulty, publication status
+- **Relationships**: author, comments, likes
+- **Media references**: filenames and metadata stored in database
+- **Benefits**: 
+  - Fast queries and searching
+  - Proper relationships and constraints
+  - ACID compliance
+  - Easy backups with database tools
+  - Scalability for large amounts of posts
+
+### File Storage
+- **Media files**: images, GPX files stored in organized folders
+- **Benefits**:
+  - Direct web server access (faster serving)
+  - Easy file management
+  - Reduced database size
+  - CDN compatibility
+
+## Database Schema
+
+### Posts Table
+- `media_folder`: String field containing the unique folder name for this post's media
+- Content stored as TEXT in the database for optimal performance
+
+### PostImage Table
+- `filename`: Stored filename (unique)
+- `original_name`: User's original filename
+- `is_cover`: Boolean indicating if this is the cover image
+- `post_id`: Foreign key to posts table
+
+### GPXFile Table
+- `filename`: Stored filename (unique)
+- `original_name`: User's original filename
+- `post_id`: Foreign key to posts table
+
+## Media Folder Naming Convention
+
+Format: `post_{8-char-uuid}_{YYYYMMDD}`
+- Example: `post_abc12345_20250723`
+- Ensures uniqueness and chronological organization
+
+## File Upload Process
+
+1. **Post Creation**: 
+   - Generate unique media folder name
+   - Create post record in database
+   - Create folder structure in `app/static/media/posts/`
+
+2. **File Upload**:
+   - Save files to post-specific subfolders
+   - Store metadata in database
+   - Generate thumbnails (for images)
+
+3. **File Access**:
+   - URLs: `/static/media/posts/{media_folder}/images/{filename}`
+   - Direct web server serving for performance
+
+## Migration and Management
+
+### Manual Migration Script
+```bash
+python manage_media.py --all
+```
+
+### Available Commands
+- `--create-folders`: Create media folders for existing posts
+- `--migrate-files`: Move files from old structure to new structure
+- `--clean-orphaned`: Remove unused media folders
+- `--stats`: Show storage statistics
+
+## Security Considerations
+
+1. **File Type Validation**: Only allowed image and GPX file types
+2. **File Size Limits**: Configurable maximum file sizes
+3. **Filename Sanitization**: Secure filename generation with UUIDs
+4. **Access Control**: Media files served through static file handler
+
+## Performance Optimizations
+
+1. **Image Compression**: Automatic JPEG compression with 85% quality
+2. **Image Resizing**: Automatic thumbnail generation and size limits
+3. **Direct File Serving**: Static files served directly by web server
+4. **CDN Ready**: File structure compatible with CDN distribution
+
+## Backup Strategy
+
+1. **Database**: Regular database backups include all post content and metadata
+2. **Media Files**: File system backups of `app/static/media/posts/` directory
+3. **Synchronization**: Media folder names in database ensure consistency
+
+## Development Notes
+
+- Post content remains in database for optimal query performance
+- Media files organized by post for easy management
+- Backward compatibility maintained for existing installations
+- Migration tools provided for seamless upgrades