chore: bump version to 0.2.0 (#33)

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` (#27, #29)
- Outbox processor scheduler refactor (#16, #17)
- Migration `OutboxStore` → plain JDBC (#26)
- `@Jvm*` annotations for Java interop (#24)
- CI hardening (environment gate #31)

## Test plan

- [x] `./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/

Author: endrju19

gradle.properties

@@ -7,4 +7,4 @@ org.gradle.caching=true
 org.gradle.configuration-cache=true
 
 GROUP=com.softwaremill.okapi
-VERSION_NAME=0.1.0
+VERSION_NAME=0.2.0