feat: cross-compile for Scala 2.12 + 2.13 and upgrade to Java 17

[fupelaqu]

Bump version to 0.9.0. Migrate JavaConverters to jdk.CollectionConverters, Configs to ConfigReader, fix .complete() syntax, add kebab-case config aliases, upgrade dependencies (generic-persistence 0.8.1, scheduler 0.8.0, notification 0.9.0, account 0.8.0, sbt plugins 0.2.0), update CI/CD workflows for JDK 17 and cross-compilation.

Closed Issue #10

[codecov]

Codecov Report

❌ Patch coverage is 55.55556% with 12 lines in your changes missing coverage. Please review.
✅ Project coverage is 40.78%. Comparing base (41b7aa0) to head (9623403).
⚠️ Report is 78 commits behind head on main.

Files with missing lines	Patch %	Lines
...ftnetwork/payment/service/StripeEventHandler.scala	0.00%	3 Missing ⚠️
...app/softnetwork/payment/spi/StripeAccountApi.scala	0.00%	3 Missing ⚠️
.../main/scala/app/softnetwork/payment/cli/Main.scala	0.00%	1 Missing ⚠️
...ent/persistence/typed/SoftPayAccountBehavior.scala	0.00%	1 Missing ⚠️
...pp/softnetwork/payment/service/ClientSession.scala	0.00%	1 Missing ⚠️
...app/softnetwork/payment/spi/MangoPayProvider.scala	80.00%	1 Missing ⚠️
...app/softnetwork/payment/spi/StripeBalanceApi.scala	0.00%	1 Missing ⚠️
...softnetwork/payment/spi/StripeDirectDebitApi.scala	0.00%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##             main      #11       +/-   ##
===========================================
- Coverage   56.01%   40.78%   -15.24%     
===========================================
  Files          46      152      +106     
  Lines        3001     9708     +6707     
  Branches        0     1557     +1557     
===========================================
+ Hits         1681     3959     +2278     
- Misses       1320     5749     +4429     

Flag	Coverage Δ
unittests	40.78% <55.55%> (-15.24%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.