fix(coach/trigger-tuner): crash after ~1h — runOnce is sync, not a Promise

The live bot died overnight with:
  TypeError: runOnce(...).catch is not a function
  at trigger-tuner.js:42  →  [supervisor] child exited code=1

attach() wrapped the timer body as `runOnce().catch(...)` but
runOnce() returns a plain {ok, flagged, ...} object (pure SQL, no
await). The first tuner tick (60min after spawn) threw → killed the
whole bot process. Never surfaced before because the bot rarely ran
uninterrupted for a full hour during development.

Fix: guard the synchronous call with try/catch, matching how
persona/chatter.js already does its sync tick. (postmortem.drainOnce
and reflect.runOnce ARE async, so their .catch is correct — audited.)

Regression test added: captures the setInterval callback and invokes
it synchronously, asserting it does not throw.

Tests: 397 green.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

runtime/coach/trigger-tuner.test.js

@@ -6,10 +6,31 @@ import { join } from "node:path";
 
 import { initKnowledge, isAvailable, listImprovements } from "../knowledge/index.js";
 import { closeStore, __resetForTests } from "../knowledge/store.js";
-import { runOnce, __testing } from "./trigger-tuner.js";
+import { runOnce, attach, detach, __testing } from "./trigger-tuner.js";
 
 const { MIN_SAMPLE } = __testing;
 
+test("attach: timer tick does not crash (runOnce is sync, regression for .catch bug)", async () => {
+	// Reproduces the crash that killed the live bot after ~1h: the
+	// setInterval body called runOnce().catch(...) but runOnce returns
+	// a plain object, not a Promise. attach must guard with try/catch.
+	detach();
+	let threw = false;
+	const origSetInterval = globalThis.setInterval;
+	let captured = null;
+	// capture the interval callback without actually waiting
+	globalThis.setInterval = (fn) => { captured = fn; return { unref() {} }; };
+	try {
+		attach({ intervalMs: 999999 });
+		// invoke the captured tick synchronously — must not throw
+		try { captured?.(); } catch { threw = true; }
+	} finally {
+		globalThis.setInterval = origSetInterval;
+		detach();
+	}
+	assert.equal(threw, false, "tuner timer tick must not throw");
+});
+
 async function bootstrap() {
 	const tmp = mkdtempSync(join(tmpdir(), "pepa-tuner-test-"));
 	__resetForTests();