Fix review findings F1 and F2 for the Dockerfile and .dockerignore

F1: derive the HEALTHCHECK port from MEALQUEST_HTTP_ADDR so an overridden
listen port is still probed at /health.
F2: make key/certificate exclusions recursive (**/*.pem, **/*.key) and add
**/*.p12, **/*.pfx, **/*.jks, **/*.keystore so nested local secrets never
enter the build context.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

.dockerignore

@@ -16,5 +16,9 @@ bin/
 .env*
 **/.env*
 deploy/secrets/
-*.pem
-*.key
+**/*.pem
+**/*.key
+**/*.p12
+**/*.pfx
+**/*.jks
+**/*.keystore