chore: enable typescript/restrict-template-expressions lint rule (#12199)

* chore: enable typescript/restrict-template-expressions lint rule

Coerce values of unknown type with explicit String() and tighten typing
for template literal expressions across the codebase.

* fix: restore --line-height on Card for fadeOut ::after gradient

plugins/github/server/api/github.ts

@@ -64,7 +64,7 @@ router.get(
     }
 
     const scopes = Object.entries(installation.permissions).map(
-      ([name, permission]) => `${name}:${permission}`
+      ([name, permission]) => `${name}:${String(permission)}`
     );
 
     const authentication = await IntegrationAuthentication.create(