Add fleet control: service configs, replica floors, monitor, pause/restart

Central fleet.json sets min/max copies. Tree-node keepFloor respawns
until three healthy unpaused replicas remain. CLI and loopback UI
pause, resume, stop, and restart instances that fail health checks.

packages/verae-fleet/src/server.js

@@ -0,0 +1,85 @@
+/**
+ * Operator HTTP: list, status, pause/resume/stop/start/restart.
+ * Binds 127.0.0.1 only.
+ * @module server
+ */
+
+import http from 'node:http';
+import fs from 'node:fs';
+import path from 'node:path';
+import { fileURLToPath } from 'node:url';
+import { listServices } from './load.js';
+
+const PUBLIC = path.join(path.dirname(fileURLToPath(import.meta.url)), '..', 'public');
+
+function json(res, code, obj) {
+  res.writeHead(code, { 'content-type': 'application/json', 'cache-control': 'no-store' });
+  res.end(JSON.stringify(obj, null, 2));
+}
+
+/**
+ * @param {import('./supervisor.js').Supervisor} sup
+ * @param {import('./monitor.js').Monitor} [mon]
+ */
+export function startControlServer(sup, mon) {
+  const bind = sup.loaded.control?.bind || '127.0.0.1';
+  const port = Number(sup.loaded.control?.port || 3850);
+
+  const server = http.createServer(async (req, res) => {
+    const url = new URL(req.url, `http://${bind}:${port}`);
+    try {
+      if (req.method === 'GET' && url.pathname === '/health') {
+        return json(res, 200, { ok: true, role: 'fleet-control' });
+      }
+      if (req.method === 'GET' && url.pathname === '/api/services') {
+        return json(res, 200, { services: listServices(sup.loaded), fleetPath: sup.loaded.fleetPath });
+      }
+      if (req.method === 'GET' && url.pathname === '/api/status') {
+        return json(res, 200, { ...sup.status(), monitor: mon?.last || null });
+      }
+      if (req.method === 'POST' && url.pathname === '/api/reconcile') {
+        const actions = await sup.reconcile();
+        return json(res, 200, { actions, status: sup.status() });
+      }
+      const svc = url.pathname.match(/^\/api\/services\/([^/]+)\/(start|stop|pause|resume)$/);
+      if (svc && req.method === 'POST') {
+        const [, id, op] = svc;
+        const fn = {
+          start: () => sup.startService(id),
+          stop: () => sup.stopService(id),
+          pause: () => sup.pauseService(id),
+          resume: () => sup.resumeService(id),
+        }[op];
+        const result = await fn();
+        return json(res, 200, { op, id, result, status: sup.status().services[id] });
+      }
+      const inst = url.pathname.match(/^\/api\/instances\/([^/]+)\/(pause|resume|restart|stop|unhealthy)$/);
+      if (inst && req.method === 'POST') {
+        const [, id, op] = inst;
+        const fn = {
+          pause: () => sup.pauseInstance(id),
+          resume: () => sup.resumeInstance(id),
+          restart: () => sup.restartInstance(id),
+          stop: () => sup.stopInstance(id, { replace: true }),
+          unhealthy: () => sup.markUnhealthy(id),
+        }[op];
+        const result = await fn();
+        return json(res, 200, { op, id, result: result?.id || result, status: sup.status() });
+      }
+      if (req.method === 'GET' && (url.pathname === '/' || url.pathname === '/index.html')) {
+        const dest = path.join(PUBLIC, 'index.html');
+        res.writeHead(200, { 'content-type': 'text/html; charset=utf-8' });
+        fs.createReadStream(dest).pipe(res);
+        return;
+      }
+      json(res, 404, { error: 'not found' });
+    } catch (err) {
+      json(res, 400, { error: err.message });
+    }
+  });
+
+  server.listen(port, bind, () => {
+    process.stdout.write(`fleet control http://${bind}:${port}/\n`);
+  });
+  return server;
+}