auditor: close the verdict→playbook loop + fix rubric-string false positive

Two changes that fell out of running the auto-loop for real on PR #8:

1. The systemd auditor blocked PR #8 on 'unimplemented!()' / 'todo!()'
   in tests/real-world/hard_task_escalation.ts — but those strings are
   the rubric itself, not macro calls. Added isInsideQuotedString()
   detection in static.ts: BLOCK_PATTERNS now skip matches that fall
   inside double-quoted / single-quoted / backtick string literals on
   the added line. WARN/INFO patterns still run — a TODO comment in
   a string is still a valid signal.

2. Verdicts were being persisted to disk but never fed back as
   learning signal. Added appendAuditLessons() — every block/warn
   finding writes a JSONL row to data/_kb/audit_lessons.jsonl with a
   path-agnostic signature (strips file paths, line numbers, commit
   hashes) so the SAME class of finding on DIFFERENT files dedups to
   one signature.

   kb_query now tails audit_lessons.jsonl and emits recurrence
   findings: 2 distinct PRs hit a signature = info, 3-4 = warn, 5+ =
   block. Severity ramps on distinct-PR count, not total rows, so a
   single unfixed PR being re-audited doesn't inflate its own
   recurrence score.

Fires on post-verdict fire-and-forget (can't break the audit if
disk write fails). The learning loop is now closed: each audit
contributes to the KB that guides the next audit.

Tested: unit tests for normalizedSignature confirmed path-agnostic
dedup; static.ts regression tests confirmed rubric strings no longer
trip BLOCK while real unquoted unimplemented!() still does.

auditor/audit.ts

@@ -12,7 +12,8 @@
 // review — reviews have self-review restrictions on Gitea and the
 // auditor currently uses the same PAT as the PR author).
 
-import { readFile, writeFile, mkdir } from "node:fs/promises";
+import { readFile, writeFile, mkdir, appendFile } from "node:fs/promises";
+import { createHash } from "node:crypto";
 import { join } from "node:path";
 import type { PrSnapshot, Verdict, Finding } from "./types.ts";
 import { getPrDiff, postCommitStatus, postIssueComment } from "./gitea.ts";
@@ -24,6 +25,10 @@ import { runInferenceCheck } from "./checks/inference.ts";
 import { runKbCheck } from "./checks/kb_query.ts";
 
 const VERDICTS_DIR = "/home/profit/lakehouse/data/_auditor/verdicts";
+// Playbook for audit findings — one row per block/warn finding from a
+// verdict. kb_query tails this next audit and escalates recurrences.
+// Structured as JSONL so it's cheap to append and cheap to tail.
+const AUDIT_LESSONS_JSONL = "/home/profit/lakehouse/data/_kb/audit_lessons.jsonl";
 
 export interface AuditOptions {
   // Skip the cloud inference call (fast path for iteration). Default false.
@@ -80,6 +85,15 @@ export async function auditPr(pr: PrSnapshot, opts: AuditOptions = {}): Promise<
 
   await persistVerdict(verdict);
 
+  // Feedback loop — every block/warn finding becomes a row in
+  // audit_lessons.jsonl, dedup-keyed by (check, normalized-summary).
+  // The next audit's kb_query reads these and escalates recurring
+  // findings so we don't lose the "this pattern has been flagged
+  // before" signal across runs. Fire-and-forget; failure here must
+  // not break the audit.
+  appendAuditLessons(verdict).catch(e =>
+    console.error(`[audit] audit_lessons append failed: ${(e as Error).message}`));
+
   if (!opts.dry_run) {
     await postToGitea(verdict);
   }
@@ -87,6 +101,42 @@ export async function auditPr(pr: PrSnapshot, opts: AuditOptions = {}): Promise<
   return verdict;
 }
 
+// Normalizes a finding summary for dedup: strips path-specific tails
+// ("in path/to/file.ts" → "in <file>"), line numbers, and long
+// commit-hash snippets. The goal is: the SAME class of finding on
+// DIFFERENT files should share a signature, so we can measure
+// "this pattern keeps showing up."
+function normalizedSignature(f: Finding): string {
+  const summary = String(f.summary)
+    .replace(/\bin\s+\S+\.(ts|rs|js|py|md)\b/gi, "in <file>")
+    .replace(/:\+?\d+\b/g, ":<line>")
+    .replace(/[0-9a-f]{8,}/gi, "<hash>")
+    .replace(/\s+/g, " ")
+    .trim()
+    .slice(0, 240);
+  const src = `${f.check}::${f.severity}::${summary}`;
+  return createHash("sha256").update(src).digest("hex").slice(0, 16);
+}
+
+async function appendAuditLessons(v: Verdict): Promise<void> {
+  const actionable = v.findings.filter(f => f.severity === "block" || f.severity === "warn");
+  if (actionable.length === 0) return;
+  await mkdir(join(AUDIT_LESSONS_JSONL, ".."), { recursive: true });
+  const rows: string[] = [];
+  for (const f of actionable) {
+    rows.push(JSON.stringify({
+      signature: normalizedSignature(f),
+      check: f.check,
+      severity: f.severity,
+      summary: f.summary,
+      pr_number: v.pr_number,
+      head_sha: v.head_sha,
+      audited_at: v.audited_at,
+    }));
+  }
+  await appendFile(AUDIT_LESSONS_JSONL, rows.join("\n") + "\n");
+}
+
 async function persistVerdict(v: Verdict): Promise<void> {
   await mkdir(VERDICTS_DIR, { recursive: true });
   const filename = `${v.pr_number}-${v.head_sha.slice(0, 12)}.json`;