v0.4.0-alpha.12

What's Changed

• docs(ga): alpha.11 G5 candidate Link soak evidence by @whshang in #88
• feat(link): G5 production cutover dry-run planner by @whshang in #89
• docs: define validation ownership matrix by @whshang in #90
• feat(link): migrate-runtime-control helper for G5 by @whshang in #91
• feat(extension): queue user inserts between turns by @whshang in #92
• chore(release): prepare Rust alpha.12 by @whshang in #93

Full Changelog: v0.4.0-alpha.11...v0.4.0-alpha.12