feat: add auto-retry (3 attempts) for file uploads on flaky connections

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/components/shared/requirement-upload-slot.tsx

@@ -166,7 +166,10 @@ export function RequirementUploadSlot({
             requirementId: requirement.id,
           })
 
-        // Upload file with progress tracking
+        // Upload file with progress tracking and auto-retry
+        const maxRetries = 3
+        for (let attempt = 1; attempt <= maxRetries; attempt++) {
+          try {
             await new Promise<void>((resolve, reject) => {
               const xhr = new XMLHttpRequest()
               xhr.upload.addEventListener('progress', (event) => {
@@ -181,11 +184,28 @@ export function RequirementUploadSlot({
                   reject(new Error(`Upload failed with status ${xhr.status}`))
                 }
               })
-          xhr.addEventListener('error', () => reject(new Error('Upload failed')))
+              xhr.addEventListener('error', () =>
+                reject(new Error('Network error during upload'))
+              )
+              xhr.addEventListener('abort', () =>
+                reject(new Error('Upload was aborted'))
+              )
               xhr.open('PUT', url)
               xhr.setRequestHeader('Content-Type', file.type)
               xhr.send(file)
             })
+            break // Success — exit retry loop
+          } catch (uploadErr) {
+            if (attempt < maxRetries) {
+              const delay = attempt * 2000
+              toast.info(`Upload interrupted, retrying... (${attempt}/${maxRetries})`)
+              setProgress(0)
+              await new Promise((r) => setTimeout(r, delay))
+            } else {
+              throw uploadErr
+            }
+          }
+        }
 
         // Save metadata
         await saveFileMetadata.mutateAsync({