feat(cli): make connect-url --relay a full anywhere pairing link

- --relay links now carry both routes: direct LAN plus relay fallback,
  matching the UI's Anywhere pairing; devices prefer the direct route
- pairing sessions created by the CLI are marked with usesRelay, and the
  server reconciles relay demand on a timer, so a headless instance
  brings the relay up on its own after connect-url --relay
- warn with LAN_UNREACHABLE when the link's direct route points at
  loopback and other devices cannot use it
- document the --relay flow and the --lan binding caveat in Connect a
  Device and Remote Instances across all locales

packages/web/server/index.js

@@ -1508,6 +1508,15 @@ async function main(options = {}) {
   // device/session exists, stop it (and clear a stale enabled flag) otherwise.
   void relayService.reconcile();
 
+  // Relay demand can change outside our routes: `openchamber connect-url
+  // --relay` writes a pending relay session straight to the on-disk store, and
+  // pending sessions expire without any request hitting us. Poll reconcile so a
+  // headless instance picks the relay up (or drops it) within a minute.
+  const relayReconcileTimer = setInterval(() => {
+    void relayService.reconcile();
+  }, 60_000);
+  relayReconcileTimer.unref?.();
+
   return {
     expressApp: app,
     httpServer: server,
@@ -1538,6 +1547,7 @@ async function main(options = {}) {
     },
     stop: (shutdownOptions = {}) => {
       realtimeProxyRuntime.stop();
+      clearInterval(relayReconcileTimer);
       try {
         relayService.stop();
       } catch {