Add detailed logging for nostrimg.com requests to diagnose 500 errors

**Motivations:**
- Diagnose why nostrimg.com returns 500 errors
- Verify if the code is causing the errors or if it's a server-side issue
- Log request and response details for troubleshooting

**Root causes:**
- Unknown: Could be code issue (wrong field name, headers, format) or server issue
- Need detailed logs to determine the cause

**Correctifs:**
- Added detailed request logging for nostrimg.com:
  - URL, method, field name, filename, content type, file size
  - All headers (Content-Type, Accept, User-Agent, Authorization)
- Added detailed response logging for nostrimg.com:
  - Status code, status message, response headers
  - Body preview (500 chars), body length, HTML detection
- Added comment about field name ('file') - some endpoints might need different names

**Evolutions:**
- None

**Pages affectées:**
- pages/api/nip95-upload.ts

pages/api/nip95-upload.ts

@@ -73,7 +73,11 @@ export default async function handler(req: NextApiRequest, res: NextApiResponse)
           // Recreate FormData for each request (needed for redirects)
           const requestFormData = new FormData()
           const fileStream = fs.createReadStream(fileField.filepath)
-          requestFormData.append('file', fileStream, {
+          
+          // Use 'file' as field name (standard for NIP-95, but some endpoints may use different names)
+          // Note: nostrimg.com might expect a different field name - if issues persist, try 'image' or 'upload'
+          const fieldName = 'file'
+          requestFormData.append(fieldName, fileStream, {
             filename: fileField.originalFilename || fileField.newFilename || 'upload',
             contentType: fileField.mimetype || 'application/octet-stream',
           })
@@ -91,6 +95,24 @@ export default async function handler(req: NextApiRequest, res: NextApiResponse)
             headers['Authorization'] = `Nostr ${authToken}`
           }
 
+          // Log request details for debugging (only for problematic endpoints)
+          if (url.hostname.includes('nostrimg.com')) {
+            console.log('NIP-95 proxy request to nostrimg.com:', {
+              url: url.toString(),
+              method: 'POST',
+              fieldName,
+              filename: fileField.originalFilename || fileField.newFilename || 'upload',
+              contentType: fileField.mimetype || 'application/octet-stream',
+              fileSize: fileField.size,
+              headers: {
+                'Content-Type': headers['content-type'],
+                'Accept': headers['Accept'],
+                'User-Agent': headers['User-Agent'],
+                'Authorization': authToken ? '[present]' : '[absent]',
+              },
+            })
+          }
+
           const requestOptions = {
             hostname: url.hostname,
             port: url.port || (isHttps ? 443 : 80),
@@ -136,6 +158,22 @@ export default async function handler(req: NextApiRequest, res: NextApiResponse)
               body += chunk
             })
             proxyResponse.on('end', () => {
+              // Log response details for debugging problematic endpoints
+              if (url.hostname.includes('nostrimg.com')) {
+                console.log('NIP-95 proxy response from nostrimg.com:', {
+                  url: url.toString(),
+                  statusCode,
+                  statusMessage: proxyResponse.statusMessage,
+                  responseHeaders: {
+                    'content-type': proxyResponse.headers['content-type'],
+                    'content-length': proxyResponse.headers['content-length'],
+                  },
+                  bodyPreview: body.substring(0, 500),
+                  bodyLength: body.length,
+                  isHtml: body.trim().startsWith('<!DOCTYPE') || body.trim().startsWith('<html') || body.trim().startsWith('<!'),
+                })
+              }
+              
               resolve({
                 statusCode: statusCode,
                 statusMessage: proxyResponse.statusMessage || 'Internal Server Error',