feat: attach screenshots during issue capture (#469)

frontend/index.html

@@ -418,6 +418,19 @@
       <label for="create-issue-body">Description <span class="small">Optional</span>
         <textarea id="create-issue-body" maxlength="10000"></textarea>
       </label>
+      <section class="create-issue-attachment" aria-labelledby="create-issue-attachment-label">
+        <strong id="create-issue-attachment-label">Screenshot <span class="small">Optional · PNG, JPEG, or WebP · 2 MB max</span></strong>
+        <div class="issue-attachment-controls">
+          <label class="issue-attachment-trigger" for="create-issue-attachment">Attach screenshot</label>
+          <input class="visually-hidden" id="create-issue-attachment" type="file" accept="image/png,image/jpeg,image/webp" />
+        </div>
+        <div class="issue-attachment-preview" id="create-issue-attachment-preview" hidden>
+          <img id="create-issue-attachment-image" alt="Selected screenshot preview" />
+          <span class="small" id="create-issue-attachment-meta"></span>
+          <button id="remove-create-issue-attachment" type="button">Remove</button>
+        </div>
+        <div class="small" id="create-issue-attachment-status" aria-live="polite"></div>
+      </section>
       <label for="create-issue-milestone">Milestone <span class="small">Optional</span>
         <select id="create-issue-milestone" aria-describedby="create-issue-milestone-status">
           <option value="">No milestone</option>