refactor(server): source build version from git tag

- Stamp version, channel and vendor into META-INF/build-info.properties
- Read build metadata at runtime from BuildProperties instead of expanded YAML
- Remove app.common placeholders from application.yaml
- Derive the OpenAPI info version from the packaged build version
- Point the OCI image source label at the GitHub repository
- Drop redundant repository blocks from settings.gradle.kts

server/settings.gradle.kts

@@ -1,14 +1 @@
-pluginManagement {
-    repositories {
-        gradlePluginPortal()
-        mavenCentral()
-    }
-}
-
-dependencyResolutionManagement {
-    repositories {
-        mavenCentral()
-    }
-}
-
 rootProject.name = "ahsarah-guide-server"