feat(xtream-proxy): rewrite proxy logic and update configuration format

Refactor the xtream-proxy from a single-file Express-based server to a
modular Node.js application using native http/https modules. This
change introduces a major version bump to 2.0.0.

- Replace `hosts.txt` with `upstreams.json` for configuration
- Remove heavy dependencies (`express`, `ws`) in favor of native modules
- Implement new environment variables for proxy credentials and timeouts
- Add `src/` directory for modular code structure
- Add `docker-compose.example.yml` for easier deployment
- Update Dockerfile to support the new directory structure and environment
- Improve error handling and probe logic for upstream selection

Dockers/xtream-proxy/src/health.js

@@ -0,0 +1,26 @@
+'use strict';
+
+const { settings } = require('./settings');
+const { getUpstreams } = require('./config');
+const {
+  getLastProbeAt,
+  rankedUpstreams,
+  describeUpstream,
+} = require('./upstreams');
+
+function healthPayload() {
+  const upstreams = getUpstreams();
+  const ranked = rankedUpstreams();
+  const selected = ranked.find((entry) => !entry.busy) || ranked[0] || null;
+
+  return {
+    ok: upstreams.some((upstream) => upstream.state.healthy),
+    configFile: settings.configFile,
+    probeIntervalSec: settings.probeIntervalSec,
+    lastProbeAt: getLastProbeAt(),
+    selected: selected ? describeUpstream(selected.upstream) : null,
+    upstreams: upstreams.map(describeUpstream),
+  };
+}
+
+module.exports = { healthPayload };