8978acdb49
hero_logo_visible is nullable — null means "inherit the global branding_logo_display_hero toggle" (#756, migration 152). But the create and update validators used `.optional()` without `{ nullable: true }`, which only skips `undefined`; an explicit `null` still ran `.isBoolean()` and failed with HTTP 400 "Invalid value". Saving an event with `hero_logo_visible: null` (the inherit state the frontend sends) was rejected on v3.45.2. - Both routes: `body('hero_logo_visible').optional({ nullable: true }).isBoolean()`, matching the already-correct `hero_logo_size` rule next to it. - Create handler: guard on `!= null` instead of `!== undefined` so an explicit null stores NULL (inherit) rather than being coerced to 0/false by formatBoolean on SQLite. The update handler already did `=== null ? null`. Left hero_logo_position on plain `.optional()` on purpose: its column is NOT NULL (no inherit migration) and its handler always resolves to a concrete value via `|| brandingDefaults`, so null is genuinely invalid there — allowing it would trade the 400 for a 500. Adds smoke tests: PUT accepts hero_logo_visible: null and stores NULL; a non-boolean value is still rejected.