Polish triggers, breadcrumbs, drawer, file preview, editable icons, logos ...

- Use btn-sm for popover, tooltip, dropdown, modal-open, confirm, toast, drawer triggers.
- Use btn-md with gap for modal and confirm-popup action buttons.
- Fix left drawer: correct SCSS nesting so .drawer-left panel slides from left.
- Align breadcrumbs demo with Figma: dark surface, active pill, collapsed rows.
- Unify File Upload preview cards with static File attachment cards markup.
- Style Editable String buttons as btn-icon-only btn-sm.
- Fix 'essentials/search' icon mapping to 'essentials/zoom/search'.
- Add Logos component block from Figma frames.
- Expand screenshot section list to cover more component demos.
- All 19 e2e tests green.

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