Report each tick's outcome and the updater's state to the master

The master saw a scheduler's last run time and nothing of what it did. Each
tick now records, per lane, its outcome, a line on what happened (what
fired, or the spread, contract or hold cap that stopped it) and why the
lane's accounts sat it out, counted by reason with a few names each. It
rides the scheduler status as lastTicks.

Each report also carries the auto-updater's state from the files it keeps
and from git: its last check, a failed update waiting to retry, how far the
checkout is behind origin, and tracked files edited by hand, which stop the
fast-forward pull.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

lib/updater-status.ts

@@ -0,0 +1,78 @@
+/**
+ * The auto-updater's state on this machine (scripts/update-check.mjs), for
+ * the master: its last check, an update that failed and waits to retry, how
+ * far the checkout is behind origin, and tracked files edited by hand — which
+ * stop the fast-forward pull. Read from the files the updater keeps and from
+ * git, and cached: the reporter asks every 30 seconds.
+ */
+
+import { execFileSync } from 'node:child_process';
+import { readFileSync } from 'node:fs';
+import path from 'node:path';
+import type { UpdaterStatus } from './master-protocol';
+
+const CACHE_MS = 2 * 60_000;
+const BRANCH = process.env.AUTOFIRMER_BRANCH ?? 'master';
+
+// Per process: instrumentation.ts and the route handlers each load this module.
+const g = globalThis as typeof globalThis & { __updaterStatus?: { at: number; status: UpdaterStatus } };
+
+function readScript(file: string): string | null {
+    try {
+        return readFileSync(path.join(process.cwd(), 'scripts', file), 'utf8');
+    } catch {
+        return null;
+    }
+}
+
+function git(args: string[]): string | null {
+    try {
+        return execFileSync('git', args, {
+            cwd: process.cwd(),
+            encoding: 'utf8',
+            stdio: ['ignore', 'pipe', 'ignore'],
+            timeout: 5_000,
+        }).trimEnd();
+    } catch {
+        return null;
+    }
+}
+
+function readFailure(): UpdaterStatus['failed'] {
+    try {
+        const f = JSON.parse(readScript('.update-failed') ?? 'null') as Record<string, unknown> | null;
+        if (!f || typeof f.target !== 'string') return null;
+        const at = Number(f.at);
+        return {
+            target: f.target.slice(0, 12),
+            step: String(f.step ?? '').slice(0, 40),
+            at: Number.isFinite(at) ? new Date(at).toISOString() : '',
+            attempts: Number(f.count) || 1,
+        };
+    } catch {
+        return null;
+    }
+}
+
+export function updaterStatus(now = Date.now()): UpdaterStatus {
+    const cached = g.__updaterStatus;
+    if (cached && now - cached.at < CACHE_MS) return cached.status;
+
+    // "<ISO time>  <status>", rewritten on every check.
+    const last = /^(\S+)\s+(.*)$/.exec(readScript('.last-check')?.trim() ?? '');
+    const behind = git(['rev-list', '--count', `HEAD..origin/${BRANCH}`]);
+    const changed = git(['status', '--porcelain', '--untracked-files=no']);
+    const status: UpdaterStatus = {
+        lastCheckAt: last ? last[1] : null,
+        lastCheck: last ? last[2].slice(0, 200) : null,
+        failed: readFailure(),
+        builtCommit: readScript('.built-commit')?.trim().slice(0, 12) || null,
+        behind: behind !== null && /^\d+$/.test(behind) ? Number(behind) : null,
+        // "XY path" per line; the status column can start with a space.
+        localChanges: changed
+            ? changed.split('\n').map((line) => line.slice(3).trim()).filter(Boolean).slice(0, 10)
+            : [],
+    };
+    g.__updaterStatus = { at: now, status };
+    return status;
+}