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.

app/media_config.py

@@ -0,0 +1,70 @@
+"""
+Media configuration settings for the motorcycle adventure community app
+"""
+
+import os
+
+class MediaConfig:
+    """Configuration for media file handling"""
+    
+    # File upload settings
+    MAX_CONTENT_LENGTH = 16 * 1024 * 1024  # 16MB max file size
+    UPLOAD_EXTENSIONS = {
+        'images': ['jpg', 'jpeg', 'png', 'gif', 'webp'],
+        'gpx': ['gpx']
+    }
+    
+    # Image processing settings
+    IMAGE_MAX_SIZE = (1920, 1080)  # Max dimensions for images
+    IMAGE_QUALITY = 85  # JPEG quality (1-100)
+    THUMBNAIL_SIZE = (300, 300)  # Thumbnail dimensions
+    
+    # Media folder settings
+    MEDIA_FOLDER = 'app/static/media/posts'
+    MEDIA_URL_PREFIX = '/static/media/posts'
+    
+    # Folder structure
+    MEDIA_SUBFOLDERS = ['images', 'gpx']
+    
+    # Security settings
+    ALLOWED_MIME_TYPES = {
+        'image/jpeg': 'jpg',
+        'image/png': 'png',
+        'image/gif': 'gif',
+        'image/webp': 'webp',
+        'application/gpx+xml': 'gpx',
+        'application/xml': 'gpx',
+        'text/xml': 'gpx'
+    }
+    
+    @staticmethod
+    def get_media_path(app, post_media_folder, subfolder=''):
+        """Get the full filesystem path to a media folder"""
+        path = os.path.join(app.root_path, 'static', 'media', 'posts', post_media_folder)
+        if subfolder:
+            path = os.path.join(path, subfolder)
+        return path
+    
+    @staticmethod
+    def get_media_url(post_media_folder, subfolder='', filename=''):
+        """Get the URL path to a media file"""
+        url = f'/static/media/posts/{post_media_folder}'
+        if subfolder:
+            url += f'/{subfolder}'
+        if filename:
+            url += f'/{filename}'
+        return url
+    
+    @staticmethod
+    def is_allowed_file(filename, file_type='images'):
+        """Check if file extension is allowed"""
+        if '.' not in filename:
+            return False
+        
+        ext = filename.rsplit('.', 1)[1].lower()
+        return ext in MediaConfig.UPLOAD_EXTENSIONS.get(file_type, [])
+    
+    @staticmethod
+    def is_allowed_mime_type(mime_type):
+        """Check if MIME type is allowed"""
+        return mime_type in MediaConfig.ALLOWED_MIME_TYPES