fix: make screenshot uploads retry-safe (#471)

frontend/dashboard.js

@@ -293,7 +293,11 @@
         'api/v1/repos/' + repository + '/issues/' + encodeURIComponent(payload.number) + '/attachments',
         {
           method: 'POST',
-          headers: { Accept: 'application/json', 'Content-Type': 'application/json' },
+          headers: {
+            Accept: 'application/json',
+            'Content-Type': 'application/json',
+            'Idempotency-Key': payload.operation_id,
+          },
           body: JSON.stringify({
             filename: payload.filename,
             content_type: payload.content_type,

frontend/issue-attachment.js

@@ -11,9 +11,16 @@
   function create(options) {
     const readDataUrl = options.readDataUrl;
     const upload = options.upload;
+    const createOperationId = options.createOperationId || (() => {
+      if (typeof globalThis !== 'undefined' && globalThis.crypto?.randomUUID) {
+        return globalThis.crypto.randomUUID();
+      }
+      return Date.now().toString(36) + '-' + Math.random().toString(36).slice(2);
+    });
     let selected = null;
     let confirmed = null;
     let serialized = null;
+    let operationId = null;
 
     function select(file) {
       if (!file || !IMAGE_TYPES.has(file.type)) {
@@ -25,6 +32,7 @@
       selected = file;
       confirmed = null;
       serialized = null;
+      operationId = createOperationId();
       return state();
     }
 
@@ -32,6 +40,7 @@
       selected = null;
       confirmed = null;
       serialized = null;
+      operationId = null;
     }
 
     function restore(value) {
@@ -80,6 +89,7 @@
           filename: attachment.filename,
           content_type: attachment.contentType,
           data: attachment.data,
+          operation_id: operationId,
         });
         if (!confirmed || typeof confirmed.markdown !== 'string' || !confirmed.markdown) {
           confirmed = null;