auditor + aibridge: 6 fixes from Opus 4.7 self-audit on PR #11

The kimi_architect auditor on commit 00c8408 ran with auto-promotion
to claude-opus-4-7 (diff > 100k chars), produced 10 grounded
findings, 1 BLOCK + 6 WARN + 3 INFO. This commit lands 6 of them; 3
are skipped (false positives or out-of-scope cleanup deferred).

LANDED:

1. kimi_architect.ts:144  empty-parse cache poisoning. When parseFindings
   returns 0 findings (markdown shape changed, prompt too big, regex
   missed every block), the verdict was still persisted with empty
   findings, and the 24h TTL cache short-circuited every subsequent
   audit with a useless "0 findings" hit. Fix: only persist when
   findings.length > 0; metrics still appended unconditionally.

2. kimi_architect.ts:122  outage negative-cache. When callKimi throws
   (network error, gateway 502, rate limit), we returned skipFinding
   but didn't note the outage anywhere. Every audit cycle within the
   24h TTL hammered the dead upstream. Fix: write a sentinel file
   `<verdict>.outage` on failure with 10-min TTL; future calls within
   that window short-circuit immediately.

3. kimi_architect.ts:331  mkdir(join(p, "..")) -> dirname(p). The
   "/.." idiom resolved correctly via Node path normalization but
   was non-idiomatic and breaks if the path ever has trailing dots.
   Both Haiku and Opus self-audits flagged it.

4. inference.ts:202  N=3 consensus latency double/triple-count.
   `totalLatencyMs += run.latency_ms` summed across THREE parallel
   `Promise.all` calls — wall-clock is bounded by the slowest, not
   the sum. Renamed to `maxLatencyMs` using `Math.max`. Telemetry now
   reports actual wall-clock instead of 3x reality.

5. continuation.rs:198,199,230,231  i64/u64 -> u32 saturating cast.
   `resp.tokens_evaluated as u32` truncates bits when source > u32::MAX
   instead of saturating. Fix: u32::try_from(...).unwrap_or(u32::MAX)
   wraps the cast in a real saturate. Applied to both the empty-retry
   loop and the structural-completion continuation loop.

SKIPPED:

- BLOCK at Cargo.lock:8911 "validator-not-in-workspace" — confabulation.
  The diff Opus saw was truncated mid-line; validator IS in
  Cargo.toml workspace members. Real-world MAX_DIFF_CHARS=180k
  edge case to watch as we feed more big diffs.
- WARN at kimi_architect.ts:248 regex absolute-path edge case — minor,
  doesn't affect grounding rate observed so far.
- INFO at inference.ts:606 "dead reconstruction loop" — Opus misread.
  The Promise.all worker fills `summaries[]`; the second loop builds
  a sequential `scratchpad` string from those. Two distinct
  operations, not redundant.

Verification:
  bun build auditor/checks/{kimi_architect,inference}.ts   compiles
  cargo check -p aibridge                                  green
  cargo build --release -p gateway                          green
  systemctl restart lakehouse.service lakehouse-auditor.service  active

Next audit cycle (~90s after push) will run on the new diff and
exercise the negative-cache + dirname + maxLatencyMs paths.

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

auditor/checks/inference.ts

@@ -169,12 +169,16 @@ export async function runInferenceCheck(
   interface Votes { trues: number; falses: number; evidences: string[] }
   const votesByClaim = new Map<number, Votes>();
   const unflaggedByRun: any[][] = [];
-  let totalLatencyMs = 0;
+  // The N=3 consensus calls run via Promise.all — wall-clock is
+  // bounded by the SLOWEST call, not the sum. Pre-2026-04-27 we
+  // summed and reported "Xms total" which double/triple-counted
+  // (Opus self-audit caught it). Use max for accurate wall-clock.
+  let maxLatencyMs = 0;
   let totalEnrichedChars = 0;
   let bugFingerprintsSeen = 0;
   let matrixKeptSeen = 0;
   for (const run of parsedRuns) {
-    totalLatencyMs += run.latency_ms ?? 0;
+    maxLatencyMs = Math.max(maxLatencyMs, run.latency_ms ?? 0);
     totalEnrichedChars += run.enriched_chars ?? 0;
     bugFingerprintsSeen = Math.max(bugFingerprintsSeen, run.bug_fingerprints ?? 0);
     matrixKeptSeen = Math.max(matrixKeptSeen, run.matrix_kept ?? 0);
@@ -199,7 +203,7 @@ export async function runInferenceCheck(
   findings.push({
     check: "inference",
     severity: "info",
-    summary: `pr_audit mode runner completed (model=${MODEL}, consensus=${parsedRuns.length}/${N_CONSENSUS}, ${totalLatencyMs}ms total)${curationNote}`,
+    summary: `pr_audit mode runner completed (model=${MODEL}, consensus=${parsedRuns.length}/${N_CONSENSUS}, ${maxLatencyMs}ms wall-clock)${curationNote}`,
     evidence: [
       `claims voted: ${votesByClaim.size}`,
       `parsed runs: ${parsedRuns.length} / ${N_CONSENSUS}`,