feature: [172] Implement native image build

[crazyrokr]

Issue

#172

Description

This PR introduces GraalVM native image build support for the MQTT Broker, enabling it to be compiled into a standalone native executable. The changes rework resource loading throughout the codebase to use InputStream-based APIs instead of direct filesystem Path access, which is essential for native images where resources must be resolved from the embedding classpath rather than the filesystem.

Changes

GraalVM Native Build Setup

• Created a dedicated native-image module that depends on application and hosts native image configuration, metadata
• Configured AOT processing with all feature flags enabled (file credentials, basic auth, external TLS)
• Added reachability-metadata.json: provides GraalVM with reflection, resource, and serialization configuration needed for the native binary

Resource Loading Refactoring

• ClassPathResourceResolver: Resolves URIs to InputStream, supporting both classpath: scheme and file: URIs. Falls back from direct filesystem access to ClassLoader.getResourceAsStream() for classpath resources - bridging the gap between JVM and native image resource resolution
• UriLoaderAuthorizationService: Replaced Path-based loading with InputStream-based loading via ClassPathResourceResolver, adds try-with-resources for proper stream lifecycle

[github-actions]

Test Coverage Report

Overall Project	85.59% -0.1%	🍏
Files changed	85.56%	🍏

File	Coverage
AclRulesLoader.groovy	100%	🍏
AclRulesLoader.java	100%	🍏
FileCredentialsSource.java	93.33%	🍏
UriLoaderAuthorizationService.java	88.71% -11.29%	❌
ClassPathResourceResolver.java	88.24% -11.76%	🍏
TlsMqttConnection.java	83.77%	🍏