Record a heartbeat so a silent update checker is distinguishable from a dead one

There was no way to tell "running, nothing to pull" from "not running". The
no-change path logs nothing by design, and PM2 reports a cron-restart process
as `stopped` with ↺ 0 even while firing on schedule — I verified that against
PM2 7.0.4: a one-minute cron fired four times without the counter moving once.

scripts/.last-check is now rewritten on every run with the outcome. It is a
single overwritten line, so it needs no trimming.

The outcome is set by each exit path and written once in `finally`, rather than
calling record at each return — the first version of this did the latter and
already missed the build-failure path.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

scripts/seed-settings 2.js

@@ -0,0 +1,31 @@
+/**
+ * Writes the reporter settings into autotrader.sqlite before first launch.
+ *
+ * lib/db.ts seeds these keys with INSERT OR IGNORE, so values written here
+ * survive the app's own startup seeding. Must be run from the project root —
+ * lib/db.ts opens the database at process.cwd().
+ *
+ *   node scripts/seed-settings.js <master_dashboard_url> <instance_name>
+ */
+const path = require('path');
+const Database = require('better-sqlite3');
+
+const [, , url, name] = process.argv;
+
+const db = new Database(path.join(process.cwd(), 'autotrader.sqlite'));
+db.exec(`
+    CREATE TABLE IF NOT EXISTS settings (
+        key   TEXT PRIMARY KEY,
+        value TEXT NOT NULL
+    );
+`);
+
+const upsert = db.prepare(
+    'INSERT INTO settings (key, value) VALUES (?, ?) ' +
+    'ON CONFLICT(key) DO UPDATE SET value = excluded.value'
+);
+
+if (url)  { upsert.run('master_dashboard_url', url);  console.log('  master_dashboard_url = ' + url); }
+if (name) { upsert.run('instance_name', name);        console.log('  instance_name        = ' + name); }
+
+db.close();