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

@@ -166,26 +166,46 @@ export function RequirementUploadSlot({
             requirementId: requirement.id,
           })
 
-        // Upload file with progress tracking
-        await new Promise<void>((resolve, reject) => {
-          const xhr = new XMLHttpRequest()
-          xhr.upload.addEventListener('progress', (event) => {
-            if (event.lengthComputable) {
-              setProgress(Math.round((event.loaded / event.total) * 100))
-            }
-          })
-          xhr.addEventListener('load', () => {
-            if (xhr.status >= 200 && xhr.status < 300) {
-              resolve()
+        // 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) => {
+                if (event.lengthComputable) {
+                  setProgress(Math.round((event.loaded / event.total) * 100))
+                }
+              })
+              xhr.addEventListener('load', () => {
+                if (xhr.status >= 200 && xhr.status < 300) {
+                  resolve()
+                } else {
+                  reject(new Error(`Upload failed with status ${xhr.status}`))
+                }
+              })
+              xhr.addEventListener('error', () =>
+                reject(new Error('Network error during upload'))
+              )
+              xhr.addEventListener('abort', () =>
+                reject(new Error('Upload was aborted'))
+              )
+              xhr.open('PUT', url)
+              xhr.setRequestHeader('Content-Type', file.type)
+              xhr.send(file)
+            })
+            break // Success — exit retry loop
+          } catch (uploadErr) {
+            if (attempt < maxRetries) {
+              const delay = attempt * 2000
+              toast.info(`Upload interrupted, retrying... (${attempt}/${maxRetries})`)
+              setProgress(0)
+              await new Promise((r) => setTimeout(r, delay))
             } else {
-              reject(new Error(`Upload failed with status ${xhr.status}`))
+              throw uploadErr
             }
-          })
-          xhr.addEventListener('error', () => reject(new Error('Upload failed')))
-          xhr.open('PUT', url)
-          xhr.setRequestHeader('Content-Type', file.type)
-          xhr.send(file)
-        })
+          }
+        }
 
         // Save metadata
         await saveFileMetadata.mutateAsync({