Watch sequential TRD follow-up rounds

[alphali]

Summary

• keep one copied context connection alive across sequential post-create Rounds for the same TRD
• preserve the approved workspace client reference when a later Round has no workspace binding yet
• fetch the current TRD before each new Round and keep code/runtime evidence separate from product intent
• release the Doable code-context plugin as 0.2.3

Verification

• npm test — 2 passed

Coordination

• getdoable/trd#413 provides connection-code resolution to the latest Round
• getdoable/qa-web#993 provides the persistent editor mailbox