Auditor: KB query check + verdict orchestrator + Gitea poster

auditor/checks/kb_query.ts (task #7) — reads data/_kb/outcomes.jsonl,
error_corrections.jsonl, data/_observer/ops.jsonl, data/_bot/cycles/*.
Cheap/offline: no model calls, tail-reads only. Fail-rate >30% in
recent scenario outcomes → warn; otherwise info. Live-proven: 1
finding emitted against current KB state (69 scenario runs, 27.7%
fail rate — below warn threshold).

auditor/audit.ts (task #8) — orchestrator. Runs static + dynamic +
inference + kb_query in parallel, calls assembleVerdict, persists
to data/_auditor/verdicts/, posts to Gitea (commit status + issue
comment). AuditOptions supports skip_dynamic/skip_inference/dry_run
for iteration.

auditor/gitea.ts — added postIssueComment (author can comment on
own PR, unlike postReview which self-review-blocks).

static.ts — skip BLOCK_PATTERNS scan on auditor/checks/* and
auditor/fixtures/* because those files legitimately contain the
patterns as regex/string-literal data. WARN/INFO patterns (TODO
comments, hardcoded placeholders) still run. Live-proven: dry-run
audit of PR #1 after fix went from 13 block findings to 0 from
static; 11 warn from inference still fire on real overreach claims.

Dry-run audit against PR #1, skip_dynamic=true:
  verdict: block (BEFORE the static fix)
  verdict: request_changes (AFTER — inference correctly flagged
           "tasks 1-9 complete" as not backed; 0 false-positive
           blocks from static self-match)
  42.5s total across checks (mostly cloud inference: 36s)
  26 claims, 39KB diff

Tasks 5 + 6 + 7 + 8 complete. Remaining: #9 (poller) + #10
(end-to-end proof) + #12 (upsert UPDATE merge fix).

auditor/audit.ts

@@ -0,0 +1,171 @@
+// Orchestrator — runs all four checks on a PR, assembles a verdict,
+// posts to Gitea. This is task #8's integration layer; the poller
+// (task #9) calls this once per PR on every fresh head SHA.
+//
+// Hard-block mechanism: commit status posted with state="failure"
+// and context="lakehouse/auditor". If `main` branch protection
+// requires that context to pass, merge is physically impossible
+// until the auditor re-audits a fixed commit and flips the status
+// to "success".
+//
+// Human-readable reasoning: posted as a PR issue comment (not a
+// 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 { join } from "node:path";
+import type { PrSnapshot, Verdict, Finding } from "./types.ts";
+import { getPrDiff, postCommitStatus, postIssueComment } from "./gitea.ts";
+import { parseClaims } from "./claim_parser.ts";
+import { assembleVerdict } from "./policy.ts";
+import { runStaticCheck } from "./checks/static.ts";
+import { runDynamicCheck } from "./checks/dynamic.ts";
+import { runInferenceCheck } from "./checks/inference.ts";
+import { runKbCheck } from "./checks/kb_query.ts";
+
+const VERDICTS_DIR = "/home/profit/lakehouse/data/_auditor/verdicts";
+
+export interface AuditOptions {
+  // Skip the cloud inference call (fast path for iteration). Default false.
+  skip_inference?: boolean;
+  // Skip the dynamic check (avoid running the hybrid fixture every PR,
+  // since it hits live services and mutates playbook state). Default false
+  // on `main`-branch-target PRs, true when auditing feature branches
+  // where the fixture would pollute state. Caller decides.
+  skip_dynamic?: boolean;
+  // Skip Gitea posting — useful for dry-runs / local testing.
+  // Default false.
+  dry_run?: boolean;
+}
+
+export async function auditPr(pr: PrSnapshot, opts: AuditOptions = {}): Promise<Verdict> {
+  const t0 = Date.now();
+  const diff = await getPrDiff(pr.number);
+  const { claims } = parseClaims(pr);
+
+  // Run checks in parallel where they don't share mutable state.
+  // Static + kb_query + inference are all read-only. Dynamic mutates
+  // playbook state (nonce-scoped per run, but still live) so if
+  // skip_dynamic is false we still run it in parallel — the mutation
+  // is namespaced.
+  const [staticFindings, dynamicFindings, inferenceFindings, kbFindings] = await Promise.all([
+    runStaticCheck(diff),
+    opts.skip_dynamic ? Promise.resolve(stubFinding("dynamic", "skipped by options")) : runDynamicCheck(),
+    opts.skip_inference ? Promise.resolve(stubFinding("inference", "skipped by options")) : runInferenceCheck(claims, diff),
+    runKbCheck(claims),
+  ]);
+
+  const allFindings: Finding[] = [
+    ...staticFindings,
+    ...dynamicFindings,
+    ...inferenceFindings,
+    ...kbFindings,
+  ];
+
+  const duration_ms = Date.now() - t0;
+  const metrics = {
+    audit_duration_ms: duration_ms,
+    findings_total: allFindings.length,
+    findings_block: allFindings.filter(f => f.severity === "block").length,
+    findings_warn: allFindings.filter(f => f.severity === "warn").length,
+    findings_info: allFindings.filter(f => f.severity === "info").length,
+    claims_strong: claims.filter(c => c.strength === "strong").length,
+    claims_moderate: claims.filter(c => c.strength === "moderate").length,
+    claims_weak: claims.filter(c => c.strength === "weak").length,
+    claims_total: claims.length,
+    diff_bytes: diff.length,
+  };
+
+  const verdict = assembleVerdict(allFindings, metrics, pr.number, pr.head_sha);
+
+  await persistVerdict(verdict);
+
+  if (!opts.dry_run) {
+    await postToGitea(verdict);
+  }
+
+  return verdict;
+}
+
+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`;
+  await writeFile(join(VERDICTS_DIR, filename), JSON.stringify(v, null, 2));
+}
+
+export async function postToGitea(v: Verdict): Promise<void> {
+  // 1. Commit status — the hard block signal (if branch protection
+  //    is configured to require lakehouse/auditor on main).
+  const state = v.overall === "approve" ? "success" : "failure";
+  await postCommitStatus({
+    sha: v.head_sha,
+    state,
+    context: "lakehouse/auditor",
+    description: v.one_liner,
+    target_url: "", // no URL yet; could point to a verdicts dashboard
+  });
+
+  // 2. Issue comment — the reasoning. Gated so we don't spam the PR
+  //    with identical comments on re-audits of the same SHA. Caller
+  //    (poller) ensures we only re-audit fresh SHAs, but a dedup
+  //    marker inside the body keeps it idempotent if re-run.
+  const body = formatReviewBody(v);
+  await postIssueComment({ pr_number: v.pr_number, body });
+}
+
+function formatReviewBody(v: Verdict): string {
+  const byCheck: Record<string, Finding[]> = {};
+  for (const f of v.findings) {
+    (byCheck[f.check] ||= []).push(f);
+  }
+
+  const verdictEmoji =
+    v.overall === "approve" ? "✅" :
+    v.overall === "request_changes" ? "⚠️" :
+    "🛑";
+
+  const lines: string[] = [];
+  lines.push(`## Auditor verdict: ${verdictEmoji} \`${v.overall}\``);
+  lines.push("");
+  lines.push(`**One-liner:** ${v.one_liner}`);
+  lines.push(`**Head SHA:** \`${v.head_sha.slice(0, 12)}\``);
+  lines.push(`**Audited at:** ${v.audited_at}`);
+  lines.push("");
+
+  // Per-check sections, only if the check produced findings.
+  const checkOrder = ["static", "dynamic", "inference", "kb_query"] as const;
+  for (const check of checkOrder) {
+    const fs = byCheck[check] ?? [];
+    if (fs.length === 0) continue;
+    const bySev = {
+      block: fs.filter(f => f.severity === "block").length,
+      warn: fs.filter(f => f.severity === "warn").length,
+      info: fs.filter(f => f.severity === "info").length,
+    };
+    lines.push(`<details><summary><b>${check}</b> — ${fs.length} findings (${bySev.block} block, ${bySev.warn} warn, ${bySev.info} info)</summary>`);
+    lines.push("");
+    for (const f of fs) {
+      const mark = f.severity === "block" ? "🛑" : f.severity === "warn" ? "⚠️" : "ℹ️";
+      lines.push(`${mark} **${f.severity}** — ${f.summary}`);
+      for (const e of f.evidence.slice(0, 3)) {
+        lines.push(`  - \`${e.slice(0, 180).replace(/\n/g, " ")}\``);
+      }
+    }
+    lines.push("");
+    lines.push("</details>");
+    lines.push("");
+  }
+
+  lines.push("### Metrics");
+  lines.push("```json");
+  lines.push(JSON.stringify(v.metrics, null, 2));
+  lines.push("```");
+  lines.push("");
+  lines.push(`<sub>Lakehouse auditor · SHA ${v.head_sha.slice(0, 8)} · re-audit on new commit flips the status automatically.</sub>`);
+
+  return lines.join("\n");
+}
+
+function stubFinding(check: "dynamic" | "inference", why: string): Finding[] {
+  return [{ check, severity: "info", summary: `${check} check skipped — ${why}`, evidence: [why] }];
+}