refactor(settings): deprecate settingsKnownSchema and integrate bird and revision settings

- Merged birdSettingsSchema and revisionSettingsSchema into settingsKnownSchema, marking the previous schema as deprecated.
- Updated emptySettingsKnownForm to utilize emptyBirdSettingsForm and emptyRevisionSettingsForm.
- Refactored layout and page components to streamline theme management and improve tab synchronization in network and operations pages.
- Introduced new system settings tab in operations and updated settings page to manage theme preferences.

.cursor/commands/commit-message.md

@@ -32,6 +32,6 @@ powershell -NoProfile -File scripts/commit/staged-context.ps1
 - Новая пользовательская возможность → `feat` (minor)
 - Починка ожидаемого поведения / баг → `fix` (patch)
 - Follow-up баги после недавнего `feat` в том же scope → **`fix`**, не `feat`
-- Только перестройка без нового поведения → `refactor` (none)
+- Только перестройка без нового поведения → `refactor` (patch, без новых функций)
 
 Заголовок — EN, императив, ≤72 символов. Тело — RU.