Refactor app-engine to correctly handle single locale configurations and update manifest type definitions. Add new test cases for localized apps with a single locale.

closes #31675

(cherry picked from commit 30efc56)

Enhance the route traversal logic to correctly identify and process wildcard route matchers (e.g., '**'). This ensures that routes with matchers are properly marked as present in the client router and handled according to their render mode.

closes #31666

(cherry picked from commit 4eb22bc)

Updates the description for the  property in the application builder's schema.
This change clarifies that both 'static' and 'server' modes generate build artifacts,
and specifies that the 'server' mode is required for applications using hybrid rendering or APIs.

(cherry picked from commit 1c4af8d)