fix: send non-JPEG images as document instead of photo; fix Dockerfile home.html path

- getFileType: only classify image/jpeg as 'photo'; png/gif/webp → 'document'
  (Telegram Bot API rejects non-JPEG for sendPhoto)
- Dockerfile: copy home.html to dist/ instead of root (import.meta.dir = dist/)
- Update test assertion for getFileType(image/png) → 'document'

test/file.test.ts

@@ -21,7 +21,7 @@ describe('File Utilities', () => {
 
     it('should classify image mime types based on caption', () => {
       expect(getFileType('image/jpeg', 'my photo')).toBe('photo');
-      expect(getFileType('image/png', 'cool image.png')).toBe('photo');
+      expect(getFileType('image/png', 'cool image.png')).toBe('document');
       expect(getFileType('image/gif', 'funny.gif')).toBe('animation');
       expect(getFileType('image/png', 'funny gif')).toBe('animation');
     });