extractor redesign: chains are the deliverable (owner-approved, goal-first)

docs/architecture.md

@@ -341,14 +341,14 @@ flowchart TB
     TRIG["trigger seam (turn-service): coverageOf(record, coverageLedger)<br/>— uncovered tokens ≥ graph.extractionChunkTokens (settings)?"] -->|"yes, single-flight per source"| RUN["extraction.runExtraction(chatId)"]
     IMPORT["POST /api/graph/import (notes front door)<br/>deterministic src id = sha256(path); content-fp guard skips unchanged re-imports"] -->|"importNotes: shared pipeline, second extractor prompt"| RUN
     RUN --> BATCH["batchRuns — greedy token-budgeted batches of oldest uncovered TEACHER-PROSE messages"]
-    BATCH --> EXT["EXTRACTOR (LLM) — sees ONLY the session markdown view<br/>(tree-blind, graph-blind; shared engine: core/session-markdown.ts)"]
+    EXT["EXTRACTOR (LLM) — sees ONLY the teacher-prose view (tree-blind, graph-blind)<br/>submits propositions + REASONING CHAINS (owner redesign, 2026-09-30),<br/>expanded to follows-edges at the seam (chainsToEdges, core/practice.ts)"]
     EXT --> AUD["AUDITOR (LLM, agentic loop) — sees findings ONLY, never the source;<br/>explores the graph via find / list_sessions / list_propositions tools,<br/>judges identity ONLY (link-or-create, equivalence bias) — never mints edges"]
     AUD --> MERGE["MERGER (deterministic, core/graph.ts) — the ONLY ledger writer:<br/>identity via validated linkTo · dedupe edges · coverage checkpoint"]
     MERGE --> SETTLE["settleGraphLayout — resting positions ledger"]
     MERGE -->|"failure at ANY stage"| NOTHING["checkpoints nothing — the next trigger re-runs"]
 ```
 
-**Raw reasoning chains only** (2026-09-27 cleanup; teacher-prose view 2026-09-28): the extractor reads ONLY the session — and since the 2026-09-28 ruling, ONLY the teacher agent's prose: plain paragraphs under the session title, no learner messages, no thinking, no tool calls or results, no quiz blocks. Coverage fingerprints, slot tokens, and batch budgets all derive from that same selection (`messageViewLines` in `core/coverage.ts`), so "covered" is exactly "what the extractor saw" — a quiz answer or learner edit can never open a run, and only a teacher-prose edit re-opens its message. The old call+result inseparability bond is deleted (nothing left to keep together); batching is pure greedy fill. The shared markdown engine (`core/session-markdown.ts`) keeps the full session format for the future user-facing export and is no longer used by extraction. The extractor proposes free-form propositions (true statements; a misconception is stated as its true correction) and `follows`/`supports` edges. The submit schemas are slim (owner, 2026-09-28): propositions carry id/name/statement/optional aliases and edges carry from/to/type — the `messages` and `evidence` fields are gone (provenance is chat-level; quote fields were never persisted and weak models burned retries on them), and a `prepareArguments` heal at the pre-validation seam rescues stringified-payload submits. Every node is an objective, world-facing fact. No quiz outcomes, no understanding assessments — the events ledger and `UnderstandingLevel` are deleted; the learner's relationship to a proposition is practice territory — which landed 2026-09-29 as **feedback-only strengthening** (§7): grades live on problem sets, and nothing ever writes learner states back to the graph.
+**Raw reasoning chains only** (2026-09-27 cleanup; teacher-prose view 2026-09-28): the extractor reads ONLY the session — and since the 2026-09-28 ruling, ONLY the teacher agent's prose: plain paragraphs under the session title, no learner messages, no thinking, no tool calls or results, no quiz blocks. Coverage fingerprints, slot tokens, and batch budgets all derive from that same selection (`messageViewLines` in `core/coverage.ts`), so "covered" is exactly "what the extractor saw" — a quiz answer or learner edit can never open a run, and only a teacher-prose edit re-opens its message. The old call+result inseparability bond is deleted (nothing left to keep together); batching is pure greedy fill. The shared markdown engine (`core/session-markdown.ts`) keeps the full session format for the future user-facing export and is no longer used by extraction. The extractor's deliverable is propositions + REASONING CHAINS (owner redesign, 2026-09-30): a chain is premises that JOINTLY entail a conclusion — independent arguments for the same conclusion are separate chains, conclusions are reusable by id as premises, and a bare proposition rides the propositions list alone. The wire schema carries propositions (id/name/statement/optional aliases) + chains (premises minItems 1/conclusion) — the `follows`/`supports` edges array is GONE from the wire, and no stage mints a `supports` edge again (supports stay in the contract/store/UI/old data; no migrations). The seam EXPANDS each chain to follows-edges (`chainsToEdges` in `core/practice.ts`, next to its inverse `chainsToGraph` — one math, one place; identical chains dedupe silently there), so `SessionFindings` and everything downstream (auditor, merge, coverage, store) are unchanged. The chain laws are enforced by the practice-proven error-back hook at the submit seam: every premise/conclusion id must resolve to a submitted proposition, premises are non-empty, no self-reference — a violation returns an error string and the model re-submits within its turns. The prompt is GOAL-FIRST, no rule armor (owner philosophy ruling, 2026-09-30): one shared `EXTRACTION_CORE` (the goal, the truth law, the submission mechanics) plus two one-sentence contextualizations — session and notes preambles — assembled at the call sites, so both front doors share the core by construction; the old defensive lists (DROP lists, merge-your-own-output, name walls, when-in-doubt-omit, the faithfulness paragraph) are all cut, and the old opening describing Quiz/Recall-check/Question blocks (stale since the teacher-prose ruling) is simply omitted. A `prepareArguments` heal at the pre-validation seam rescues stringified-payload submits (propositions or chains). Every node is an objective, world-facing fact. No quiz outcomes, no understanding assessments — the events ledger and `UnderstandingLevel` are deleted; the learner's relationship to a proposition is practice territory — which landed 2026-09-29 as **feedback-only strengthening** (§7): grades live on problem sets, and nothing ever writes learner states back to the graph.
 
 **Serialized audit, parallel extracts — per-chunk jobs** (owner ruling 2026-09-28): every chunk (notes file) and every batch (chat coverage) is its own JOB — registry row, usage record, failure domain. Extracts fan out in parallel across all jobs and sources, throttled by a process-wide 3-permit extract semaphore on `globalThis` (the provider-facing rate stance; a job waiting for a permit shows `queued`). The audit→merge section remains a process-wide FIFO critical section — a mutex on `globalThis` (the same module-instance idiom as the run registries): before any auditor LLM call or graph read, a job waits (`waiting` phase) until every earlier job's merge has landed, so each auditor explores the graph as it actually stands — two concurrent audits would each link into a graph the other is about to change, the structural mint of duplicate nodes. Failure isolation: one job failing (bad chunk, degraded model output) is absorbed at the fan-out — its messages stay uncovered and honestly re-runnable while its siblings still merge; the run returns what actually merged. Abort is source-wide: every job of a source's fan-out dies together, and merged jobs keep their checkpoints. The status feed shows one row per job (`file.md · 2/5` suffixes for chunked sources), and each job persists its own usage record (failed jobs bill their partial spend too).