Promote workspace adapter transaction contract

[Hisakazu333]

Summary

• promote the already-merged stacked transaction/migration contract into dev/hisakazu
• carries PR Add workspace adapter transaction contract #206 changes after runtime bridge entry reaches dev/hisakazu

Merge order

• merge Promote NekoBuddy workspace runtime bridge entry #207 first so this PR diff shrinks to the transaction contract only

Verification

• upstream stacked PR Add workspace adapter transaction contract #206 CI passed
• local check confirmed dev/hisakazu does not contain the transaction contract commit yet

[Hisakazu333]

Closing this promotion PR because the stacked branch history conflicts with dev/hisakazu after #204 merged. Replacing with a clean promotion branch based directly on dev/hisakazu.