Notes front door: format-agnostic import into the graph pipeline

The same extractor→auditor→merger pipeline now runs over raw personal
notes in arbitrary formats (vision §1, DECIDED 2026-09-13):

- NotesSource records (data/graph/sources.json, deterministic id from
  path hash → idempotent re-imports) play the chatId role in mappings,
  checkpoints, and observation events; usage lands on the source record
  (appendSourceUsage, idempotent per startedAt, kept across upserts).
- mergeFindings is chat-store-free: callers pass MergeSource
  {messages, foldedAt} — sessions pass the chat record, notes pass
  messages:null (no quiz-event rebuild; a deterministic rebuild needs
  structured quiz tool parts).
- Second extractor prompt (NOTES_EXTRACTOR_INSTRUCTIONS) for general-
  purpose extraction; understanding judges the AUTHOR's grasp. Auditor
  wording input-agnostic. extract/audit share one generic runSubmitAgent.
- graphSnapshot.fileSources (srcId→filePath); notes sources render as
  static path entries in the detail card (FileTextIcon, never a link).
- One shared pipeline instance (exported from chat-handler): same
  single-flight registry, live status chips (label = file path), usage
  accounting, and true abort for both front doors.
- Transport: POST /api/graph/import (multipart, 3-wide worker pool) +
  Import notes… button in the graph view; scripts/import-notes.ts for
  batch runs (concurrency 4).
- real-data-extraction/ gitignored (raw import sources never committed).

355/355 tests; typecheck, lint, build green.

scripts/import-notes.ts

@@ -0,0 +1,62 @@
+/**
+ * Import raw notes files through the format-agnostic front door (vision §1,
+ * 2026-09-13) — every *.md / *.txt file in a directory becomes one
+ * extraction run (extractor → auditor → merger) over its raw text. Run
+ * from this worktree only — data never crosses trees:
+ *
+ *   npx tsx --env-file=.env.local scripts/import-notes.ts <dir> [concurrency]
+ *
+ * Default dir: real-data-extraction/learn-sessions (the prototype
+ * learning-session exports — deliberately NOT imported as chats: they run
+ * through the notes path, raw). Runs in this process: the dev server's
+ * status chips do NOT see them (registry is per-process) — the dev server
+ * sees runs triggered through /api/graph/import.
+ */
+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";
+
+async function main() {
+	const dir = process.argv[2] ?? "real-data-extraction/learn-sessions";
+	const limit = Number(process.argv[3] ?? 4);
+	const files = fs
+		.readdirSync(dir)
+		.filter((f) => f.endsWith(".md") || f.endsWith(".markdown") || f.endsWith(".txt"))
+		.sort();
+	console.log(`[import-notes] ${files.length} note files from ${dir} (concurrency ${limit})`);
+
+	const pipeline = createExtractionPipeline(stores);
+	const queue = [...files];
+	const totals = { nodes: 0, edges: 0, events: 0, failed: 0 };
+	const workers = Array.from({ length: Math.min(limit, files.length) }, async () => {
+		for (;;) {
+			const file = queue.shift();
+			if (!file) return;
+			const filePath = path.join(dir, file);
+			const t0 = Date.now();
+			try {
+				const stats = await pipeline.importNotes({ filePath, text: fs.readFileSync(filePath, "utf-8") });
+				totals.nodes += stats.nodes;
+				totals.edges += stats.edges;
+				totals.events += stats.events;
+				console.log(
+					`[import-notes] ${file}: ${stats.nodes} nodes, ${stats.edges} edges, ${stats.events} events in ${((Date.now() - t0) / 1000).toFixed(1)}s`,
+				);
+			} catch (err) {
+				totals.failed++;
+				console.error(`[import-notes] ${file} FAILED:`, err);
+			}
+		}
+	});
+	await Promise.all(workers);
+
+	const graph = getGraph(stores.graphStore);
+	console.log(
+		`[import-notes] done: +${totals.nodes} nodes, +${totals.edges} edges, +${totals.events} events, ${totals.failed} failed — ` +
+			`graph now ${graph.nodes.length} nodes, ${graph.edges.length} edges, ${graph.events.length} events`,
+	);
+}
+
+main();