chore: bump version to 0.2.0

[endrju19]

Bumps VERSION_NAME from 0.1.0 to 0.2.0 ahead of release.

After this merges I will create the v0.2.0 tag, which will trigger the publish job (gated on maven-central environment — needs your approval in the Actions UI).

What's in v0.2.0

The auto-generated draft is at https://github.com/softwaremill/okapi/releases — covers ~15 PRs since v0.1.0, including:

• Observability module okapi-micrometer (feat: Observability — OutboxProcessorListener + okapi-micrometer module (KOJAK-44) #27, fix(micrometer): publish artifact + document okapi.metrics.refresh-interval #29)
• Outbox processor scheduler refactor (feat: config unification — Duration migration + OutboxPurgerConfig (KOJAK-61) #16, feat: multi-datasource transaction validation (KOJAK-63) #17)
• Migration OutboxStore → plain JDBC (feat: migrate OutboxStore from Exposed to plain JDBC (KOJAK-64) #26)
• @Jvm* annotations for Java interop (feat: @Jvm* annotations for Java interoperability (KOJAK-65) #24)
• CI hardening (environment gate ci: gate Maven Central publish on maven-central environment #31)

Test plan

• ./gradlew build zielone na main przed bumpem (CI on every preceding PR)
• After merge: git tag v0.2.0 && git push --tags
• Approve Publish to Maven Central job in Actions UI
• Verify artifacts on https://repo1.maven.org/maven2/com/softwaremill/okapi/