v0.3.0 release playtest checklist

[xefensor]

Goal

Run and record the final release-candidate verification for Retold v0.3.0.

Automated validation

• ./gradlew clean build
• ./gradlew runGameTestServer
• GitHub Actions checks pass

In-game validation

• Fresh-world progression
• Existing-world compatibility and backup warning
• Singleplayer smoke test
• Dedicated-server smoke test
• Multiplayer portals, dimensions, and progression
• Air Temple discovery and Gale Core encounter
• Aender portal travel, regeneration, and stabilizers
• Visual and audio changes reviewed with screenshots or recordings

Release preparation

• Version and supported dependency values are correct
• Changelog contains a complete 0.3.0 entry
• Modrinth, CurseForge, and GitHub descriptions agree
• JAR and SHA-256 checksum are produced
• Known limitations are documented

Target: v0.3.0