Owner ruling 2026-10-04: the module is a sunk cost, retrievable from
history if ever revisited. Removed: core practice contracts + pipeline
helpers, the PracticeStore port + adapter + data dir path, server
service + API routes (sets, clusters picker, practice aborts), the
practice pages + dialog/exam/list UI, chain-table's Generate handoff,
sidebar nav, activity-dock practice rows, and the partitioner/
problemGenerator/grader model roles (BACKGROUND_MODEL_ROLES 8 → 5).
Survivors, moved to core/chains.ts (pure + browser-safe): ReasoningChain,
chainsForSelection, formatChainLine — the chain table and graph
emission still consume them.
Rulings: each problem generation is its own visible dock job (the
extraction per-chunk pattern), and practice shares extraction's
semaphore — one process-wide 3-permit pool for ALL background LLM
jobs; total background LLM concurrency bounded at 3.
A. SHARED POOL: new src/agent/subagents/bg-llm-semaphore.ts —
globalThis __lhLlmSlots, PERMIT_COUNT 3 (the ruling), the
fresh-take/handed-off-permit deadlock discipline preserved for
BOTH callers. extraction.ts's withExtractSlot is now a thin
wrapper (job-row signal → withBgLlmSlot); __lhExtractSlots and
__lhPracticeSlots both die. The partitioner now acquires a permit
too (it's a background LLM job — it didn't before).
B. REGISTRY ROWS: the aggregate setId:generation / setId:grading rows
are replaced by setId:partition (phase partitioning, label
'Partitioning — title'), setId:gen:problemId (queued→generating,
'Problem i/N — title'), setId:grade:problemId (queued→grading,
'Grading i/N — title'). Each row carries its OWN abort controller
and its OWN usage (one PracticeStepLog per row — the aggregate
partitioner/generator/grader folding dies). Row key = feed id =
abort key (the dock dup-key law).
C. ABORT SEMANTICS: abortPracticeRow(key) routes by shape — gen row:
THAT problem only (error 'Aborted', siblings continue, set settles
ready with one errored problem); partition row: the whole run;
grade row: that grade drops (answer kept, re-submittable).
abortPractice(setId) composes from row aborts + the synchronous
persisted marks (a set-abort's verdict stands before the settles
re-read it — the settle step keeps an existing error status).
/api/activity/abort kind practice now takes the ROW key (charset
admits ':').
D. FEED + DOCK: ActivityPractice/FeedPractice carry per-row identity
(id = row key, problemIndex/problemTotal); dock blobs render per
row, labels carry the i/N; the aggregate row is gone.
E. Boot sweep unchanged at set grain; the live-row check is now a
key-prefix scan (any live row of the set protects it). The
updatedAt heartbeat covers the new row scheme as-is.
Tests (20 in the pipeline suite): per-problem row shape/uniqueness/
i-N labels (partition row frozen behind a gated partitioner; per-row
usage ISOLATION pin — b's log never shows on c's row); abort-one-gen
(sibling completes, set ready with one errored problem); partition-
row abort; queued grade-row abort (dead-ticket path: answer kept,
re-submittable, sibling lands); shared-pool identity + contention
(practice queues behind extraction-style holders); registry/dock
feed mapping. Test isolation hardened: unique per-store set ids,
afterEach registry/lock/pool reset (a timed-out test can no longer
poison the rest).
architecture.md: jobs-pattern paragraph rewritten (per-problem rows,
shared pool, abort routing).
1149/1149, tsc 0, lint 0, build 0.
Owner ruling 2026-09-25. runPiTurn executes a turn decoupled from any HTTP
response: an unbounded memory-only event log (finite by construction; the
30-min liveness TTL bounds the pathological case) plus a subscriber set.
The POST /api/chat stream and the new GET /api/chats/[id]/stream are both
subscribers — identical SSE dialect; late subscribers get FULL replay
(starting at the start chunk) then live until finish + [DONE]. A view
cancelling (reload, navigate) now detaches ONLY — never aborts the turn.
The remote kill is the abort channel: POST /api/activity/abort gains
kind: "turn" (id = chatId; not_running 409 like jobs); handle.abort sets
sawAbort + agent.abort(), every subscriber closes cleanly, the partial
persists through the usual settle (onFinish runs once, then endTurn,
then unregisterTurn LAST so a view that finds nothing finds the record
current). No running turn on reattach: the cheap terminal — one
{"type":"turn-settled"} event + [DONE] (settledTurnResponse).
The live smoke caught what the unit suite had masked: the agent_end
close() had been left behind in the restructure — ReferenceError every
turn, steered into the error path; fixed and pinned (clean turns must
never emit an error chunk; finishReason stop present).
The dock is visible in every view, so it needs every running process —
sub-agent jobs across ALL chats (not just the open one) plus the global
extraction runs — in one poll. /api/jobs stays chat-scoped and untouched:
it is the transcript machinery's poll and carries turnInFlight for the
re-attach seam (chat-transport), the seam we spent three live rounds
stabilizing; making it polymorphic would fork its response shape by mode
and put regression risk on exactly the wrong path. The dock is a different
consumer with a different shape (cross-chat, running-only, cost-bearing),
served by a thin route over server/observability.ts:
- activityFeed(): running jobs from every chat (title-joined, oldest-first
on last activity) + extraction runs + busyChats (chats with a teacher
turn in flight — the biggest spender; data made available, rendering is
a dock decision).
- GET /api/activity — the dock's single poll everywhere.
- Cost math stays client-side (core/prices.ts folds); raw usage rides the
records and the transport stays thin.
Decided with the user over the polymorphic-/api/jobs and
separate-all-jobs-endpoint alternatives.
amosblomqvist