[Feature] Version-aware `hensu-server` native binary

[alxsuv]

Description

Currently the hensu-server native image always reports hensu-server 0.1.0-SNAPSHOT in its Quarkus startup banner, regardless of which GitHub release tag (e.g. server/v0.1.0-beta.1) the artifact was built
from. Make the binary's reported version match the release tag so downloads from the GitHub Releases page are self-identifying.

Scope

• Build: In root build.gradle.kts:11, replace the literal version = "0.1.0-SNAPSHOT" with a parameterized read using a distinct property name (e.g. findProperty("releaseVersion")?.toString() ?: "0.1.0-SNAPSHOT"). A distinct name is required because Gradle's project.version defaults to "unspecified", which would bypass an elvis fallback on findProperty("version").
• CI: In .github/workflows/release-server.yml (resolve-version step at lines 23–34 already exports $VERSION from a server/v* tag), append -PreleaseVersion=$VERSION to the existing native build
  invocation. Do not introduce a new tag-parsing regex.
• Runtime: No code change required. Quarkus' default startup banner already interpolates quarkus.application.version, which the Quarkus Gradle plugin auto-populates from the project version. Skip any
  @ConfigProperty injection or IVersionProvider work.

Acceptance criteria

• Local ./gradlew :hensu-server:quarkusDev (no -PreleaseVersion) still prints hensu-server 0.1.0-SNAPSHOT.
• A release build with -PreleaseVersion=0.1.0-beta.1 prints hensu-server 0.1.0-beta.1 in the banner.
• Native image produced by release-server.yml for tag server/v0.1.0-beta.1 reports 0.1.0-beta.1 on startup.
• No new reflection, classpath scanning, or runtime config lookups introduced (native-safety invariants preserved).

Out of scope

• Adding a dedicated --version CLI subcommand.
• Changing the GitHub release tag naming convention.
• Native-image integration tests (tracked separately; see README.md:319).