Fix fournisseur handling across catalog flows

app/composables/useApi.js

@@ -29,10 +29,27 @@ export function useApi () {
       clearTimeout(timeoutId)
 
       if (response.ok) {
-        const data = await response.json()
+        let data = null
+        if (response.status !== 204) {
+          const contentType = response.headers.get('content-type') || ''
+          if (contentType.includes('application/json')) {
+            const text = await response.text()
+            data = text ? JSON.parse(text) : null
+          } else {
+            const text = await response.text()
+            data = text || null
+          }
+        }
         return { success: true, data }
       } else {
-        const errorData = await response.json().catch(() => ({}))
+        const contentType = response.headers.get('content-type') || ''
+        let errorData = {}
+        if (contentType.includes('application/json')) {
+          errorData = await response.json().catch(() => ({}))
+        } else {
+          const text = await response.text().catch(() => '')
+          errorData = text ? { message: text } : {}
+        }
         const errorMessage = errorData.message || `Erreur ${response.status}: ${response.statusText}`
         showError(errorMessage)
         return { success: false, error: errorMessage, status: response.status }