Use a ZIP-compatible default project build output timestamp

[martinfrancois]

Suggested review order: 12 of 52 (Score: 7.5)
Review first: openrewrite/rewrite-static-analysis#1007

What's changed?

Changes the default project build output timestamp from 1980-01-01T00:00:00Z to the earliest ZIP-compatible value, 1980-01-01T00:00:02Z, and updates the generated recipe metadata and examples.

What's your motivation?

Recipe: org.openrewrite.maven.cleanup.AddProjectBuildOutputTimestamp.

I found this by running org.openrewrite.maven.cleanup.AddProjectBuildOutputTimestamp from org.openrewrite:rewrite-maven:8.87.0 on pom.xml in Symphony-Trello at a8013f27. I reproduced the same result with the latest released recipe artifact, org.openrewrite:rewrite-maven:8.90.0, using org.openrewrite.maven:rewrite-maven-plugin:6.46.1. Running maven-pmd-plugin:3.28.0:pmd on the transformed checkout fails with: '1980-01-01T00:00:00Z' is not within the valid range 1980-01-01T00:00:02Z to 2099-12-31T23:59:59Z.

Before

<properties>
  <java.version>25</java.version>
</properties>

Actual after the recipe

<properties>
  <java.version>25</java.version>
  <project.build.outputTimestamp>1980-01-01T00:00:00Z</project.build.outputTimestamp>
</properties>

Expected after the recipe

<properties>
  <java.version>25</java.version>
  <project.build.outputTimestamp>1980-01-01T00:00:02Z</project.build.outputTimestamp>
</properties>

ZIP timestamps have a two-second resolution and reject the emitted value. The recipe therefore adds a property that makes a normal Maven reporting goal fail.

Confirmed real-world execution

• Project: Symphony-Trello.
• Location: pom.xml at a8013f27.
• Discovery checkout: martinfrancois/symphony-trello@a8013f27.

Anything in particular you'd like reviewers to focus on?

Please review the two-second lower bound and the synchronized updates to the generated example and recipe metadata.

Have you considered any alternatives or workarounds?

Projects can override the generated timestamp manually. The recipe should nevertheless emit a default accepted by ZIP-producing Maven plugins.

Any additional context

Pre-existing tests changed: ReproducibleBuildsTest.java.appliesEncodingAndOutputTimestamp (updated), AddProjectBuildOutputTimestampTest.java.addsDefaultTimestamp (updated), AddProjectBuildOutputTimestampTest.java.addsToExistingPropertiesBlock (updated).

• Target commit: martinfrancois/symphony-trello@a8013f27
• Discovery release: org.openrewrite:rewrite-maven:8.87.0
• Latest verification release: org.openrewrite:rewrite-maven:8.90.0
• Focused tests: AddProjectBuildOutputTimestampTest

This change was prepared with AI assistance. I reviewed the target execution evidence, implementation, tests, generated metadata, and contribution text.

Checklist

• I've added unit tests to cover both positive and negative cases
• I've read and applied the recipe conventions and best practices
• I've run ./gradlew build locally, and committed any resulting changes to recipes.csv
• I've formatted the lines I changed, without reformatting code I didn't touch