fix(editor): preserve consecutive whitespace in comments in TipTap

Ensure multiple spaces in comment content are no longer collapsed when editing/saving by:
- Adding SetContentOptions with parseOptions.preserveWhitespace = 'full'
- Applying those options to all setContent calls (initial load, exit edit mode, post-upload cleanup)
- Enabling preserveWhitespace in editor parseOptions

Previously, repeated spaces were normalized away after setContent(false), causing comments with deliberate spacing to be altered unexpectedly.

No behavioral changes beyond whitespace retention; renders identical except space fidelity.

frontend/src/components/input/editor/TipTap.vue

@@ -145,7 +145,7 @@ import {eventToHotkeyString} from '@github/hotkey'
 import EditorToolbar from './EditorToolbar.vue'
 
 import StarterKit from '@tiptap/starter-kit'
-import {Extension, mergeAttributes} from '@tiptap/core'
+import {Extension, mergeAttributes, type SetContentOptions} from '@tiptap/core'
 import {EditorContent, type Extensions, useEditor, VueNodeViewRenderer} from '@tiptap/vue-3'
 import {Plugin, PluginKey} from '@tiptap/pm/state'
 import {marked} from 'marked'
@@ -213,6 +213,12 @@ const tiptapInstanceRef = ref<HTMLInputElement | null>(null)
 
 const {t} = useI18n()
 
+const defaultSetContentOptions: SetContentOptions = {
+	parseOptions: {
+		preserveWhitespace: 'full',
+	},
+}
+
 const CustomTableCell = TableCell.extend({
 	addAttributes() {
 		return {
@@ -539,6 +545,9 @@ const editor = useEditor({
 	onUpdate: () => {
 		bubbleNow()
 	},
+	parseOptions: {
+		preserveWhitespace: 'full',
+	},
 })
 
 watch(
@@ -583,7 +592,7 @@ function bubbleSave() {
 }
 
 function exitEditMode() {
-	editor.value?.commands.setContent(lastSavedState, false)
+	editor.value?.commands.setContent(lastSavedState, defaultSetContentOptions)
 	if (isEditing.value) {
 		internalMode.value = 'preview'
 	}
@@ -630,7 +639,7 @@ function uploadAndInsertFiles(files: File[] | FileList) {
 		
 		const html = editor.value?.getHTML().replace(UPLOAD_PLACEHOLDER_ELEMENT, '') ?? ''
 		
-		editor.value?.commands.setContent(html, false)
+		editor.value?.commands.setContent(html, defaultSetContentOptions)
 		
 		bubbleSave()
 	})
@@ -689,7 +698,7 @@ onBeforeUnmount(() => {
 
 function setModeAndValue(value: string) {
 	internalMode.value = isEditorContentEmpty(value) ? 'edit' : 'preview'
-	editor.value?.commands.setContent(value, false)
+	editor.value?.commands.setContent(value, defaultSetContentOptions)
 }