Diagnosis (2026-09-11 user testing, minimal-effort GLM): sessions stuck on
'plan' forever. Two causes: (1) the three-phase view read the stored tree's
currentNodeId, which nothing ever writes post author-once (2026-09-03) — a
structural dead seam; (2) the teacher stochastically left quiz.nodeId
untagged, and done-by-quiz-result semantics would have falsely completed
nodes anyway.
The redesign (docs/probe-teach-split.md) abolishes derived occupancy in
favor of explicit events:
- Two agents over one transcript: createProberAgent (quiz without a
nodeId field, ask, probe_done) and createTeacherAgent (full toolset,
plan_init onward). The chat-handler construction branch keys on a
probe_done part in the transcript. MODELS.prober added.
- probe_done: server-side seam tool — carries the learner assessment
(strands + free-form edge read), refuses while a question is open or
the probe is already concluded, and queues a handoff steer through the
generalized wake pipeline (steers now dedupe by id, not jobId; job
finalization only for job steers). The teacher auto-wakes and authors
the plan; the learner sees the assessment via the probe-done card.
- phases: probe ends at a concluded probe_done, plan ends at a
successful plan_init — strictly sequential, no skipping, no legacy
compatibility (data wiped at the pivot per doctrine).
- Plan map = position, not completion: derivePlanStatuses reads only
tagged quiz CALLS (state/outcome feed nothing); current = latest
tagged node with consecutive duplicates collapsed, visited = earlier
distinct stays (a revisit stays in both — current wins at render).
PlanTree is structure-only; currentNodeId/doneNodeIds and the dead
mutation helpers are gone. No fallback current.
- Prompts split per agent (prompts/prober/, prompts/teacher/ over the
trimmed shared base); graph-context injection removed entirely
(shelved, docs/probe-teach-split.md §5); knowledge-graph context no
longer reaches either agent.
- Plan blocks are full-only snapshots at plan_init (neighborhood
machinery retired; the persistent DAG window is the future UI wave);
usage capture unchanged.
Gates: tsc clean, 294/294 tests (phases/plan-tree/plan-blocks/question-
tools rewritten to the new semantics; probe-done + handoff-wake tests
added), lint, build. Live GLM smoke PASS: prober concluded with an honest
assessment, teacher auto-woke, authored a 10-node plan with the block
attached, then tagged checks on slope-instinct → secant derived current/
visited exactly as designed; grading honest both ways (driver off-by-one
proved a wrong answer grades false).
- components/phase-divider.tsx: PhaseChip (header, next to the session
title: phase-colored dot + Probing/Planning/Teaching) and PhaseDivider
(the transcript boundary: color-coded dotted rules + a small chip —
'Plan · N nodes' at the plan seam, 'Teaching' at the teach seam; probe
never renders, phases only advance). planNodeCount reads the seam
message's first plan tree.
- chat.tsx: dividers render at MESSAGE boundaries (phaseTimeline, one
linear fold) — the seam is the transition to the message's phase, so
the seam message's prose sits below its divider. requiresReveal now
uses phaseAt3 teach (an occupied node), so probe- AND plan-phase
questions auto-open.
- Retired the part-level plan-divider (artifact registry): the boundary
is message-level, not part-level. Its tests replaced by
render-phase-divider tests; core/phases gains tested phaseTimeline.
- core/phases.ts: Phase3 (probe/plan/teach) + pure derivations —
phaseOfTree (point-in-time, from the stored plan tree: no nodes → probe,
no occupied node → plan, occupied → teach) and phaseAt3 (monotonic
transcript fold for the dividers: failed plan_init never marks a seam;
phase only advances).
- contracts.ts: ChatSummary gains record-derived phase + pendingQuestion;
ChatListItem adds liveness-merged busy.
- store/chats.ts listChats computes the record-derived fields (tree +
pending question scan).
- api/chats route merges busy = turn running || running background job.
Lane crossing granted by master: contracts/store/api (schema arbitration).
Data-only inference: pre-plan planning reads as probe until the plan lands.