feat: major project restructure - move Django to backend dir and fix critical imports

- Restructure project: moved Django backend to backend/ directory
- Add frontend/ directory for future Next.js application
- Add shared/ directory for common resources
- Fix critical Django import errors:
  - Add missing sys.path modification for apps directory
  - Fix undefined CATEGORY_CHOICES imports in rides module
  - Fix media migration undefined references
  - Remove unused imports and f-strings without placeholders
- Install missing django-environ dependency
- Django server now runs without ModuleNotFoundError
- Update .gitignore and README for new structure
- Add pnpm workspace configuration for monorepo setup

static/js/photo-gallery.js

@@ -1,91 +0,0 @@
-document.addEventListener('alpine:init', () => {
-    Alpine.data('photoDisplay', ({ photos, contentType, objectId, csrfToken, uploadUrl }) => ({
-        photos,
-        fullscreenPhoto: null,
-        uploading: false,
-        uploadProgress: 0,
-        error: null,
-        showSuccess: false,
-
-        showFullscreen(photo) {
-            this.fullscreenPhoto = photo;
-        },
-
-        async handleFileSelect(event) {
-            const files = Array.from(event.target.files);
-            if (!files.length) {
-                return;
-            }
-
-            this.uploading = true;
-            this.uploadProgress = 0;
-            this.error = null;
-            this.showSuccess = false;
-
-            const totalFiles = files.length;
-            let completedFiles = 0;
-
-            for (const file of files) {
-                const formData = new FormData();
-                formData.append('image', file);
-                formData.append('app_label', contentType.split('.')[0]);
-                formData.append('model', contentType.split('.')[1]);
-                formData.append('object_id', objectId);
-
-                try {
-                    const response = await fetch(uploadUrl, {
-                        method: 'POST',
-                        headers: {
-                            'X-CSRFToken': csrfToken,
-                        },
-                        body: formData
-                    });
-
-                    if (!response.ok) {
-                        const data = await response.json();
-                        throw new Error(data.error || 'Upload failed');
-                    }
-
-                    const photo = await response.json();
-                    this.photos.push(photo);
-                    completedFiles++;
-                    this.uploadProgress = (completedFiles / totalFiles) * 100;
-                } catch (err) {
-                    this.error = err.message || 'Failed to upload photo. Please try again.';
-                    console.error('Upload error:', err);
-                    break;
-                }
-            }
-
-            this.uploading = false;
-            event.target.value = ''; // Reset file input
-
-            if (!this.error) {
-                this.showSuccess = true;
-                setTimeout(() => {
-                    this.showSuccess = false;
-                }, 3000);
-            }
-        },
-
-        async sharePhoto(photo) {
-            if (navigator.share) {
-                try {
-                    await navigator.share({
-                        title: photo.caption || 'Shared photo',
-                        url: photo.url
-                    });
-                } catch (err) {
-                    if (err.name !== 'AbortError') {
-                        console.error('Error sharing:', err);
-                    }
-                }
-            } else {
-                // Fallback: copy URL to clipboard
-                navigator.clipboard.writeText(photo.url)
-                    .then(() => alert('Photo URL copied to clipboard!'))
-                    .catch(err => console.error('Error copying to clipboard:', err));
-            }
-        }
-    }));
-});