Cross-compile SoftPayment for Scala 2.12 + 2.13 and upgrade to Java 17

[fupelaqu]

Summary

Cross-compile the SoftPayment project for both Scala 2.12.20 and 2.13.16, and upgrade from JDK 8 to JDK 17.

Changes

• Add crossScalaVersions and moduleSettings to build.sbt
• Bump version from 0.8.3.1 to 0.9.0
• Upgrade JDK target from 8 to 17 (javacOptions, Docker base image, CI/CD)
• Migrate scala.collection.JavaConverters → scala.jdk.CollectionConverters
• Migrate configs.Configs → configs.ConfigReader API
• Fix .complete() call syntax for Scala 2.13 compatibility
• Add base-url kebab-case aliases in reference.conf files
• Upgrade dependencies: generic-persistence, scheduler, notification, account, sbt plugins, scalapb-extensions, scoverage, scala-parser-combinators
• Add scala-collection-compat for cross-version compatibility
• Add explicit slf4j-api and logback-classic dependencies
• Update GitHub Actions workflows (checkout v4, setup-java v4, JDK 17, cross-compile step, coverage)
• Add JVM --add-opens flags for Java 17 module system
• Fork tests (Test / fork := true)

Story

Story 5.10-pre-2-d: Cross-Compile SoftPayment (2.12 + 2.13) + Java 17