Add image upload to property form via FilesController

- Added uploadPicture() API function for POST /Files/UploadPicture
- Images uploaded immediately on selection, paths stored
- PropertyInformation.images sent with server-side paths
- Remove image also removes from uploaded paths

app/utils/api.js

@@ -196,6 +196,32 @@ export async function getCurrencies() {
   return apiFetch('/Currency/GetAll');
 }
 
+// ─── Files ───
+
+export async function uploadPicture(file) {
+  console.log('[API] Uploading picture:', file.name);
+  const formData = new FormData();
+  formData.append('file', file);
+  const token = AuthService.getToken();
+  const res = await fetch(`${API_BASE}/Files/UploadPicture`, {
+    method: 'POST',
+    headers: {
+      ...(token && { Authorization: `Bearer ${token}` }),
+    },
+    body: formData,
+  });
+  const text = await res.text();
+  console.log('[API] Upload response:', res.status, text?.substring(0, 100));
+  if (!res.ok) throw new Error(`Upload failed: ${res.status} ${text}`);
+  // Response is the relative path string (possibly in envelope)
+  try {
+    const json = JSON.parse(text);
+    return json?.data || json;
+  } catch {
+    return text;
+  }
+}
+
 // ─── Auth: Registration ───
 
 /**