Method constructor

tracker/src/hub.ts:28–105

(
    private loop: ControlLoop,
    private upstream: Upstream,
    private recorder: Recorder,
    private video: VideoStream,
    private videoRec: VideoRecorder,
  )

  private stateTimer: ReturnType<typeof setInterval> | null = null;

  constructor(
    private loop: ControlLoop,
    private upstream: Upstream,
    private recorder: Recorder,
    private video: VideoStream,
    private videoRec: VideoRecorder,
  ) {
    const app = express();
    // The debug UI is served from :3000 but talks to this tracker on :3001 of
    // the SAME host, so its fetch()es are cross-origin. Allow cross-port reads
    // from the same hostname (covers prod :3000, dev :5173, and LAN-IP access)
    // while still rejecting foreign origins; answer the CORS preflight.
    app.use((req, res, next) => {
      const origin = req.headers.origin;
      if (origin) {
        let sameHost = false;
        try {
          sameHost = new URL(origin).hostname === req.hostname;
        } catch {
          /* malformed Origin — treat as not allowed */
        }
        if (sameHost) {
          res.setHeader("Access-Control-Allow-Origin", origin);
          res.setHeader("Vary", "Origin");
          res.setHeader("Access-Control-Allow-Methods", "GET, POST, DELETE, OPTIONS");
          res.setHeader("Access-Control-Allow-Headers", "content-type");
        }
      }
      if (req.method === "OPTIONS") return res.sendStatus(204);
      next();
    });
    app.use(express.json());

    app.get("/api/tracker/health", (_req, res) => res.json({ ok: true }));
    app.get("/api/tracker/state", (_req, res) => res.json(this.loop.getState()));
    app.get("/api/tracker/config", (_req, res) =>
      res.json(this.upstream.getConfig().tracker),
    );
    app.get("/video", (_req, res) => this.video.addClient(res));
    app.get("/frame.jpg", (_req, res) => {
      const frame = this.video.latestFrame();
      if (!frame) return res.status(503).json({ error: "no frame yet" });
      res.type("image/jpeg").send(frame);
    });
    // The frame as the detector sees it: red = masked clutter, green = blob.
    app.get("/vision-debug.jpg", (_req, res) => {
      const frame = this.video.latestFrame();
      if (!frame) return res.status(503).json({ error: "no frame yet" });
      renderDebug(frame)
        .then((img) => res.type("image/jpeg").send(img))
        .catch((err) => res.status(500).json({ error: String(err) }));
    });

    // --- full-quality clip recording ---
    app.post("/api/record/video", (req, res) => {
      if (req.body?.on) res.json(this.videoRec.start());
      else {
        this.videoRec.stop();