Migrate language widget to signals (#1535)

* Migrate language widget to signals and adopt @if/@for template syntax

Migrate all three language widget components (display, record-view, edit)
from decorator-based @Input/@output to Angular signal APIs (input, output,
computed, signal). Update S3 widget template and CLAUDE.md coding conventions
to require built-in control flow (@if, @for) over structural directives.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* s3 widget fix

---------

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

Author: gugu

frontend/package.json

@@ -49,7 +49,7 @@
 		"lodash-es": "^4.17.21",
 		"mermaid": "^11.12.1",
 		"monaco-editor": "0.55.1",
-		"ng-dynamic-component": "^10.7.0",
+		"ng-dynamic-component": "^10.8.0",
 		"ngx-cookie-service": "^19.0.0",
 		"ngx-markdown": "^19.1.1",
 		"ngx-stripe": "^19.0.0",