fix(studio): connect to the active channel, not hard-coded :50051

Studio defaulted its endpoint to the local channel's port (:50051), but
a curl|sh user is on the production channel (:50071) — so the sidebar
probed a different daemon than the Diagnose page reported, showing
'connected' next to 'production daemon stopped'. On first run Studio now
reads ~/.chain/current-channel (+ run/<ch>.endpoint) and follows the
active channel; an explicit Settings endpoint still wins and persists,
auto-discovery does not (re-follows the channel each launch). The
connection caption now names the channel ('Connected · production') so
it can never look contradictory again.

Signed-off-by: flemming-it <stefan.a.flemming@googlemail.com>

lib/data/hub.dart

@@ -5,6 +5,7 @@
 // Methods return UI-friendly types so pages stay free of
 // protobuf imports.
 
+import 'dart:io';
 import 'dart:typed_data';
 
 import 'package:chain_client_sdk/chain_client_sdk.dart';
@@ -28,10 +29,79 @@ class HubService {
 
   HubEndpoint get currentEndpoint => _client.endpoint;
 
+  /// The channel Studio is connected to, discovered from
+  /// `~/.chain/current-channel` when no explicit endpoint was set.
+  /// Shown next to the connection caption so "connected" names which
+  /// daemon — never contradicting the Diagnose page again.
+  String? activeChannel;
+
+  /// Best-effort name of the channel the current endpoint targets,
+  /// matched by its well-known port (50071 → production). Falls back to
+  /// the auto-discovered channel. `null` for a custom host/port.
+  String? get connectedChannelName {
+    final port = _client.endpoint.port;
+    for (final e in _channelPorts.entries) {
+      if (e.value == port) return e.key;
+    }
+    return activeChannel;
+  }
+
   static const _kHostKey = 'hub.host';
   static const _kPortKey = 'hub.port';
   static const _kSecureKey = 'hub.secure';
 
+  /// gRPC default ports per channel (mirror of the Rust
+  /// `Channel::default_port`). Used as the fallback when the daemon
+  /// has not written its `run/<channel>.endpoint` file yet.
+  static const _channelPorts = {
+    'local': 50051,
+    'dev': 50041,
+    'beta': 50061,
+    'production': 50071,
+  };
+
+  /// The endpoint of the channel the operator is actually on, read
+  /// from `~/.chain` (the hub writes `current-channel` and, when a
+  /// daemon is up, `run/<channel>.endpoint`). Lets a fresh Studio
+  /// follow the installed channel — a `curl | sh` user lands on
+  /// `production` (:50071), not the hard-coded local :50051. Returns
+  /// null when it cannot be determined (then we keep the default).
+  static ({String channel, HubEndpoint endpoint})? _discoverActiveChannel() {
+    try {
+      final home = Platform.environment['HOME'] ??
+          Platform.environment['USERPROFILE'];
+      if (home == null || home.isEmpty) return null;
+      final sep = Platform.pathSeparator;
+      final base = '$home$sep.chain';
+      final ccFile = File('$base${sep}current-channel');
+      final channel =
+          ccFile.existsSync() ? ccFile.readAsStringSync().trim() : 'local';
+      if (channel.isEmpty) return null;
+      // Prefer the actual bound endpoint the daemon wrote.
+      final epFile = File('$base${sep}run$sep$channel.endpoint');
+      if (epFile.existsSync()) {
+        final raw =
+            epFile.readAsStringSync().trim().replaceFirst(RegExp(r'^\w+://'), '');
+        final i = raw.lastIndexOf(':');
+        if (i > 0) {
+          final host = raw.substring(0, i);
+          final port = int.tryParse(raw.substring(i + 1));
+          if (port != null) {
+            return (channel: channel, endpoint: HubEndpoint(host: host, port: port));
+          }
+        }
+      }
+      // Fall back to the channel's well-known default port.
+      return (
+        channel: channel,
+        endpoint:
+            HubEndpoint(host: '127.0.0.1', port: _channelPorts[channel] ?? 50051),
+      );
+    } catch (_) {
+      return null;
+    }
+  }
+
   /// Sentinel distinguishing "caller did not pass authToken"
   /// from "caller passed null to drop the token".
   static const Object _unset = Object();
@@ -45,32 +115,59 @@ class HubService {
     final port = prefs.getInt(_kPortKey);
     final secure = prefs.getBool(_kSecureKey);
     final token = await HubAuthToken.read();
-    if (host == null && token == null) return;
-    final endpoint = HubEndpoint(
-      host: host ?? _client.endpoint.host,
-      port: port ?? _client.endpoint.port,
-      secure: secure ?? _client.endpoint.secure,
-    );
-    await reconnect(endpoint, authToken: token);
+
+    // 1) An endpoint the operator explicitly chose in Settings wins.
+    if (host != null) {
+      await reconnect(
+        HubEndpoint(
+          host: host,
+          port: port ?? _client.endpoint.port,
+          secure: secure ?? false,
+        ),
+        authToken: token,
+      );
+      return;
+    }
+
+    // 2) Otherwise follow the active channel from ~/.chain, so Studio
+    //    connects to the daemon the operator installed (e.g. production
+    //    :50071) instead of the hard-coded local :50051. Not persisted,
+    //    so Studio re-discovers each launch and tracks channel switches.
+    final discovered = _discoverActiveChannel();
+    if (discovered != null) {
+      activeChannel = discovered.channel;
+      await reconnect(discovered.endpoint, authToken: token, persist: false);
+      return;
+    }
+
+    // 3) Nothing to discover: keep the default client, apply any token.
+    if (token != null) {
+      await reconnect(_client.endpoint, authToken: token, persist: false);
+    }
   }
 
-  /// Reconnect to a new endpoint and persist for next launch.
-  /// [authToken] is read from `~/.chain/hub-auth-token` by
-  /// default — pass `null` to drop a previously-loaded token,
-  /// or omit the parameter to keep the current value.
+  /// Reconnect to a new endpoint. With [persist] (the default) the
+  /// endpoint is saved for next launch — that is an explicit operator
+  /// choice. Auto-discovery passes `persist: false` so it never
+  /// overwrites a real choice and keeps re-following the active channel.
+  /// [authToken] is read from `~/.chain/hub-auth-token` by default —
+  /// pass `null` to drop a token, or omit to keep the current value.
   Future<void> reconnect(
     HubEndpoint endpoint, {
     Object? authToken = _unset,
+    bool persist = true,
   }) async {
     await _client.close();
     final token = identical(authToken, _unset)
         ? await HubAuthToken.read()
         : authToken as String?;
     _client = HubClient(endpoint: endpoint, authToken: token);
-    final prefs = await SharedPreferences.getInstance();
-    await prefs.setString(_kHostKey, endpoint.host);
-    await prefs.setInt(_kPortKey, endpoint.port);
-    await prefs.setBool(_kSecureKey, endpoint.secure);
+    if (persist) {
+      final prefs = await SharedPreferences.getInstance();
+      await prefs.setString(_kHostKey, endpoint.host);
+      await prefs.setInt(_kPortKey, endpoint.port);
+      await prefs.setBool(_kSecureKey, endpoint.secure);
+    }
   }
 
   /// Reload the token from disk and reconnect using the current

lib/main.dart

@@ -763,8 +763,11 @@ class _SidebarState extends State<_Sidebar>
                   Builder(
                     builder: (context) {
                       final l = AppLocalizations.of(context)!;
+                      final ch = HubService.instance.connectedChannelName;
                       final caption = widget.connected == true
-                          ? l.connectionConnected
+                          ? (ch != null
+                                ? '${l.connectionConnected} · $ch'
+                                : l.connectionConnected)
                           : widget.connected == false
                           ? l.connectionTapToStart
                           : l.connectionConnecting;
@@ -1127,8 +1130,12 @@ class _ConnectionLabel extends StatelessWidget {
     final captionColor = connected == false
         ? theme.colorScheme.error
         : theme.colorScheme.onSurface;
+    // Name the channel the connection is on (production / local / …) so
+    // "connected" can never look like it contradicts the Diagnose page,
+    // which reports the *active* channel's daemon.
+    final ch = HubService.instance.connectedChannelName;
     final caption = connected == true
-        ? l.connectionConnected
+        ? (ch != null ? '${l.connectionConnected} · $ch' : l.connectionConnected)
         : connected == false
         ? l.connectionTapToStart
         : l.connectionConnecting;