auditor: integrate Kimi second-pass review (off by default, LH_AUDITOR_KIMI=1)

Adds kimi_architect as a fifth check kind in the auditor. Runs
sequentially after static/dynamic/inference/kb_query, consumes their
findings as context, and asks Kimi For Coding "what did everyone
miss?" — targeting load-bearing issues that deepseek N=3 voting can't
see (compile errors, false telemetry, schema bypasses, determinism
leaks). 7/7 grounded on the distillation v1.0.0 audit experiment
2026-04-27.

Off by default. Enable on the lakehouse-auditor service:
  systemctl edit lakehouse-auditor.service
  Environment=LH_AUDITOR_KIMI=1

Tunable env (all optional):
  LH_AUDITOR_KIMI_MODEL       default kimi-for-coding
  LH_AUDITOR_KIMI_MAX_TOKENS  default 12000
  LH_GATEWAY_URL              default http://localhost:3100

Guardrails:
- Failure-isolated. Any Kimi error / 429 / TOS revocation returns a
  single info-level skip-finding so the existing pipeline never blocks
  on a Kimi outage.
- Cost-bounded. Cached verdicts at data/_auditor/kimi_verdicts/<pr>-
  <sha>.json with 24h TTL — re-audits within the window return cached
  findings instead of re-calling upstream. New commits produce new
  SHAs so caching is per-head, not per-day.
- 6min upstream timeout (vs 2min for openrouter inference) — Kimi is
  a reasoning model and the audit prompt is large.
- Grounding verification baked in. Every finding's cited file:line is
  greppped against the actual file before the verdict is persisted.
  Per-finding evidence carries [grounding: verified at FILE:LINE] or
  [grounding: line N > EOF] / [grounding: file not found]. Confab-
  ulation rate goes into data/_kb/kimi_audits.jsonl as grounding_rate
  for "is this still valuable" tracking.

Persisted artifacts:
  data/_auditor/kimi_verdicts/<pr>-<sha>.json   full verdict + raw
                                                Kimi response + grounding
  data/_kb/kimi_audits.jsonl                    one row per call:
                                                latency, tokens, findings,
                                                grounding rate

Verdict-rendering: kimi_architect now appears in the per-check
sections of the human-readable comment posted to PRs (auditor/audit.ts
checkOrder), after kb_query.

Verification:
  bun build auditor/checks/kimi_architect.ts   compiles
  bun build auditor/audit.ts                   compiles
  parser sanity (3-finding fixture)            3/3 lifted correctly

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

auditor/audit.ts

@@ -23,6 +23,7 @@ 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";
+import { runKimiArchitectCheck } from "./checks/kimi_architect.ts";
 
 const VERDICTS_DIR = "/home/profit/lakehouse/data/_auditor/verdicts";
 // Playbook for audit findings — one row per block/warn finding from a
@@ -67,6 +68,29 @@ export async function auditPr(pr: PrSnapshot, opts: AuditOptions = {}): Promise<
     ...kbFindings,
   ];
 
+  // Kimi-architect second-pass review. Off by default; enabled with
+  // LH_AUDITOR_KIMI=1. Sequential (not in the parallel block above)
+  // because it consumes the prior findings as context — Kimi sees what
+  // deepseek already flagged and is asked "what did everyone miss?"
+  // Failure-isolated by design: any error returns a single info-level
+  // skip finding so the existing audit pipeline never blocks on Kimi.
+  if (process.env.LH_AUDITOR_KIMI === "1") {
+    try {
+      const kimiFindings = await runKimiArchitectCheck(diff, allFindings, {
+        pr_number: pr.number,
+        head_sha: pr.head_sha,
+      });
+      allFindings.push(...kimiFindings);
+    } catch (e) {
+      allFindings.push({
+        check: "kimi_architect",
+        severity: "info",
+        summary: `kimi_architect outer error — ${(e as Error).message.slice(0, 160)}`,
+        evidence: [(e as Error).stack?.slice(0, 360) ?? ""],
+      });
+    }
+  }
+
   const duration_ms = Date.now() - t0;
   const metrics = {
     audit_duration_ms: duration_ms,
@@ -184,7 +208,7 @@ function formatReviewBody(v: Verdict): string {
   lines.push("");
 
   // Per-check sections, only if the check produced findings.
-  const checkOrder = ["static", "dynamic", "inference", "kb_query"] as const;
+  const checkOrder = ["static", "dynamic", "inference", "kb_query", "kimi_architect"] as const;
   for (const check of checkOrder) {
     const fs = byCheck[check] ?? [];
     if (fs.length === 0) continue;
@@ -217,6 +241,6 @@ function formatReviewBody(v: Verdict): string {
   return lines.join("\n");
 }
 
-function stubFinding(check: "dynamic" | "inference", why: string): Finding[] {
+function stubFinding(check: "dynamic" | "inference" | "kimi_architect", why: string): Finding[] {
   return [{ check, severity: "info", summary: `${check} check skipped — ${why}`, evidence: [why] }];
 }