Clarify clean continuation-thread assumption

docs/HYPERTWIST_MODEL_A_MODEL_B_COORDINATOR_DOCTRINE_2026-05-14.md

@@ -174,6 +174,13 @@ For the current clean-room sequence:
 - that reuse is legal only if the conversation remained clean, the standing
   reconciled note or checkpoint note was written first, and the repo and bound
   were explicitly selected before coding
+- for continuation inside an already-open clean bounded implementation thread,
+  the coordinating instance may allow the prompt to assume cleanliness when
+  that thread was initialized from the clean prompt and no contrary evidence
+  exists
+- the coordinating instance should not force redundant cleanliness dialogue in
+  that case; the fallback is a new clean thread only when the existing thread
+  is suspect, known non-clean, or stricter audit separation is wanted
 - shared cross-lane reconciliation is an exception checkpoint, not the default
   immediate next step after every contribution pass
 - repo-local and shared reconciliation are additive, not reset-oriented

docs/HYPERTWIST_PHASE_5R_CLEAN_ROOM_PROMPT_AND_HANDOFF_PACKET_2026-05-14.md

@@ -215,6 +215,12 @@ Clean `Model B` bounded implementation:
 - the clean coordinating instance may serve as consolidation instance and
   immediate implementation instance if it has remained clean and has not been
   source-exposed
+- if that already-open bounded implementation thread was initialized from the
+  clean prompt and no contrary evidence exists, a continuation prompt may
+  assume cleanliness and say `continue in this same clean Model B bounded
+  implementation thread`
+- if the thread is known to have become source-exposed, it must not continue
+  as the clean implementation thread
 
 ## Primer rule