Record F38 and F39

The agent guessed an undocumented schema and was never told it guessed wrong.
The operator noticed the stall before the system reported anything.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011xsXyr5J1RACo71YeKG3Pu

BURNIN.md

@@ -1607,3 +1607,32 @@ implement launch -> correction above accepted plan above accepted research
 The correction is held until the plan successor is definitely live. Posting
 earlier still exercises F20 and F23, but it cannot prove a mid-plan correction
 outranks accepted research and the current trajectory.
+
+### F38 and F39: the agent guessed a schema, and was never told it guessed wrong
+
+Run 5 sealed `research.json` at 01:47:52 and wrote
+`{"from": "research", "to": "plan"}`. Nothing moved for five minutes. The
+operator noticed before the system reported anything.
+
+```text
+research artifact: json: cannot unmarshal string into Go struct
+field Research.dead_ends of type workphase.DeadEnd
+```
+
+F38: the brief said `Seal .orchestra/research.json before you ask` and
+described the contents in prose. It never stated the schema. The agent wrote
+`dead_ends` as strings where the decoder wants `{tried, why_failed}` objects.
+Everything else in the artifact was correct.
+
+F39: `requestPhase` refused through `recordError` alone. `answerRefusedPhase`
+ran only on a coordinator 409, so a local decode failure reached nobody. The
+session parked at a boundary with no feedback, and worker health holds one
+error slot (F18), so even that trace was overwritable.
+
+F39 is the serious half. F38 alone costs one corrected file. F39 turns any
+local refusal into a silent stall.
+
+Fixed in `0bd86e2`. The brief carries the shape, and every local refusal now
+reaches the agent. `TestPhaseSealSchemasDecode` decodes each documented shape
+with the function the worker uses: flipping `dead_ends` back to strings
+reproduces run 5's exact error at build time.