Angular: v21.2.12 Release

core

| Commit | Description | | -- | -- | | | allow explicit read generic with signal input transforms | | | i18n flags leaking on errors | | | respect ngSkipHydration on components with projectable nodes in LContainers | | | sanitizer typings | | | validate security-sensitive attributes in i18n bindings | | | visit ng-let expression value in signal migration schematics |

forms

| Commit | Description | | -- | -- | | | prohibit concurrent submits in signal forms |