feat: manage mobile checklist steps inline (Closes #919)

frontend/index.html

@@ -605,6 +605,18 @@
     <button class="issue-retry" id="retry-issue-load" type="button" hidden>Reload latest issue</button>
     <div class="row"><span id="issue-labels"></span><span class="small" id="issue-assignees"></span></div>
     <div class="issue-sheet-content markdown-content" id="issue-sheet-body"></div>
+    <form class="checklist-step-editor" id="checklist-step-editor" aria-label="Manage checklist step" hidden>
+      <label for="checklist-step-label">Checklist step</label>
+      <input id="checklist-step-label" type="text" maxlength="240" autocomplete="off" />
+      <div class="checklist-step-editor-actions">
+        <button id="save-checklist-step-edit" type="submit">Rename</button>
+        <button id="move-checklist-step-earlier" type="button">Move earlier</button>
+        <button id="move-checklist-step-later" type="button">Move later</button>
+        <button id="remove-checklist-step" type="button">Remove</button>
+        <button id="cancel-checklist-step-edit" type="button">Cancel</button>
+      </div>
+      <div id="checklist-step-edit-status" class="small" aria-live="assertive"></div>
+    </form>
     <section class="checklist-add" aria-label="Add checklist step">
       <button id="open-add-checklist-step" type="button" disabled>Add step</button>
       <form id="add-checklist-step-form" hidden>