bdb8cab1c9
- Add replaces_tab column to InfoPage ('faq','rules','privacy','offer')
- Migration 0067: add nullable replaces_tab column
- CRUD: clear_replaces_tab ensures one page per tab, get_tab_replacements
returns {tab: slug} mapping for active pages
- Admin routes: auto-clear old assignment on create/update
- Public route: GET /info-pages/tab-replacements (no auth)
- Schemas: replaces_tab with regex validation in all request/response models