feat: Maven plugin: support locally-stored PAT as fallback to TIMEFOLD_PAT env var

[oemebamo]

This is a proposal to improve https://github.com/TimefoldAI/timefold-solver-enterprise/issues/806

[sonarqubecloud]

Quality Gate passed

Issues
1 New issue
0 Accepted issues

Measures
0 Security Hotspots
88.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[mswiderski]

I would prefer to avoid storing secrets (PAT in this case) in clear text in user's home directory. Since we are talking about maven plugin I would expect we follow standard practice of maven https://maven.apache.org/guides/mini/guide-encryption.html that way we could rely on exactly the same mechanism as all others plugins that require secrets to communicate with remote service. Plus this can also take advantage of encryption to not keep it clear text.

[oemebamo]

I would prefer to avoid storing secrets (PAT in this case) in clear text in user's home directory. Since we are talking about maven plugin I would expect we follow standard practice of maven https://maven.apache.org/guides/mini/guide-encryption.html that way we could rely on exactly the same mechanism as all others plugins that require secrets to communicate with remote service. Plus this can also take advantage of encryption to not keep it clear text.

excellent; thanks for the pointer - didn't know about this standard practice