Extraction-UX data layer: the chunk budget becomes a graph setting; the chat view gets a per-session coverage read

Owner-locked extraction-UX redesign (dispatch 2026-09-24), part 1 (data
layer; the UI chunk follows).

THRESHOLD -> SETTING
- config.ts's EXTRACTION.chunkTokens dies; the default moves into
  FACTORY_SETTINGS.graph.extractionChunkTokens (4096, the old constant's
  value). GraphSettings gains the optional field, Required at resolution
  via the standard ?? FACTORY pattern — pre-redesign records resolve the
  default cleanly.
- FLOOR 500 (the implementer's call, documented on the field): every run
  pays the graph-carrying prompt overhead out of the write channel's
  money — a smaller budget fires penny-batches that cost more per
  extracted token than the content is worth. The sanitizer CLAMPS up
  (bd68486 clamp-never-reject discipline: fractions floor, junk drops);
  the settings PUT REJECTS below-floor with the rationale in the message.
  No ceiling: a large budget just delays extraction — the user's stated
  cost/thoroughness tradeoff, not a misconfiguration to police.
- The trigger (turn-service.triggerExtraction) takes the budget as a
  parameter — chat-handler passes effective.graph.extractionChunkTokens,
  the fresh per-turn read, same as every other gate.
- The pipeline's BATCH side threads through the same number:
  ExtractionPipelineDeps gains an OPTIONAL getChunkTokens getter with the
  factory default (Teacher's 24 test fixtures stay untouched; the two
  call-site lines inside extraction.ts are the only cross-band edits,
  flagged). chat-handler + backfill/import-notes wire the live
  effectiveSettings — trigger and batches share one budget, always.

PER-SESSION COVERAGE READ
- sessionCoverage(chatId) (server/chats.ts): the chat view's ring-meter
  block — totalMessages/coveredCount/uncoveredCount/coveredTokens/
  uncoveredTokens (the same coverageOf derivation /api/graph/coverage
  serves, scoped to one chat), running (chat-kind extraction registered
  for this id), and lastFoldedAt (the chat's newest coverage row's fold
  — a cheap single pass; null before any fold). GET /api/chats/[id]
  carries it as coverage: {...}; unknown chat -> null (the route 404s
  first).
- /api/graph/coverage (the all-sessions list) compiles untouched — the
  per-session read is a scoping of it, not a supersession; the UI's
  sidebar/ring chunk decides which surface it consumes.

Tests: factory/sanitizer pins (clamp-up, fraction-floor, junk-drop),
resolution pins (absent -> 4096, stored 2000 wins), settings-body pins
(valid/absent/fraction/below-floor 400/junk 400), sessionCoverage pins
(derived split, newest-fold scoping, cross-session isolation, running via
the registry, null on unknown chat). 893/893.

scripts/backfill-graph.ts

@@ -9,12 +9,18 @@ import { chatStore } from "../src/store/chats.ts";
 import { graphStore } from "../src/store/graph.ts";
 import { createExtractionPipeline } from "../src/agent/subagents/extraction.ts";
 import { getGraph } from "../src/core/graph.ts";
+import { effectiveSettings } from "../src/server/stores.ts";
 
 async function main() {
 	const only = process.argv[2]; // optional: extract just one chat id
 	const chats = only ? chatStore.listChats().filter((c) => c.id === only) : chatStore.listChats();
 	console.log(`[backfill] ${chats.length} chats to extract`);
-	const pipeline = createExtractionPipeline({ chatStore, graphStore });
+	const pipeline = createExtractionPipeline({
+		chatStore,
+		graphStore,
+		// Live budget: the graph section's setting, same as the app's trigger
+		getChunkTokens: () => effectiveSettings().graph.extractionChunkTokens,
+	});
 	for (const chat of chats) {
 		const t0 = Date.now();
 		try {

scripts/import-notes.ts

@@ -16,7 +16,7 @@ import * as fs from "node:fs";
 import * as path from "node:path";
 import { createExtractionPipeline } from "../src/agent/subagents/extraction.ts";
 import { getGraph } from "../src/core/graph.ts";
-import { stores } from "../src/server/stores.ts";
+import { effectiveSettings, stores } from "../src/server/stores.ts";
 
 async function main() {
 	const dir = process.argv[2] ?? "real-data-extraction/learn-sessions";
@@ -27,7 +27,11 @@ async function main() {
 		.sort();
 	console.log(`[import-notes] ${files.length} note files from ${dir} (concurrency ${limit})`);
 
-	const pipeline = createExtractionPipeline(stores);
+	const pipeline = createExtractionPipeline({
+		...stores,
+		// Live budget: the graph section's setting, same as the app's trigger
+		getChunkTokens: () => effectiveSettings().graph.extractionChunkTokens,
+	});
 	const queue = [...files];
 	const totals = { nodes: 0, edges: 0, events: 0, failed: 0 };
 	const workers = Array.from({ length: Math.min(limit, files.length) }, async () => {