feat(builder): modern grouped rich-text toolbar with icons and tooltips

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

P0 user feedback: unstyled B/I/U/H2/List/1,2,3 buttons were not understandable for non-technical users.

- Toolbar buttons grouped by intent (text style | headings | lists | insert | advanced) with visual separators, hover states, consistent 30px hit targets
- Icons (PrimeIcons) for list/link/image/table/divider/code/embed; B/I/U keep their conventional letters but rendered in their own style (bold/italic/underline) as every mainstream editor does; every button gets a translated tooltip and aria-label (en/ru/hy)
- Code view toggle moved to the right edge, visually de-emphasized - it is the expert path, not a primary action
- Toolbar visually attaches to the editing surface (shared border, joined radius) so it reads as one control

src/app/i18n/translations.ts

@@ -685,6 +685,20 @@ export interface Translations {
     linkVisibleDesc: string;
     appName: string;
     backToDashboard: string;
+    htmlToolBold: string;
+    htmlToolItalic: string;
+    htmlToolUnderline: string;
+    htmlToolHeading: string;
+    htmlToolSubheading: string;
+    htmlToolBulletList: string;
+    htmlToolNumberedList: string;
+    htmlToolLink: string;
+    htmlToolImage: string;
+    htmlToolTable: string;
+    htmlToolDivider: string;
+    htmlToolCodeBlock: string;
+    htmlToolEmbed: string;
+
     breadcrumbRoot: string;
     statusComplete: string;
     statusInProgress: string;