Resolves the AiPostWizard conflict and completes the feature:
- i18n parity: brand_colors_label + brand_colors_description in all 15 locales
(was en/es/pt-BR only, which broke LocalizationParityTest).
- Reworked the two-button toggle into a Switch with an explanatory description
(matches the settings Switch/card pattern).
- Only shown for templates that honor the flag: added appliesBrandVisuals() to
the AiContentTemplate contract (ImageCard=true, tweet cards=false), exposed as
applies_brand_visuals in the create-page DTO, and gated the toggle on it — so
it no longer appears (as a no-op) for tweet-card styles.
- Tests: TemplateContractTest covers appliesBrandVisuals for all templates.
- Top switcher (Compose / Channels / Preview / Comments) reveals the panel that was hidden below lg
- Sticky bottom action bar puts schedule/publish/delete within thumb reach
- Composer media actions and comment toolbar are visible on touch (no hover needed); media grid is 3-up
- Clamp media picker and emoji picker widths to the viewport
Add full lang/ translations for fr, de, it, nl, pl, el, ja, ko, zh, ru,
tr, and ar — all 23 base files each, with identical key trees to lang/en,
preserved :placeholders and plural forms, and native product terminology.
