Broadcast Text pull-out (Live screen) + launch geometry 1920x1040/1366x768 with restore

Services/YouTubeStreamService.cs

@@ -2,9 +2,9 @@ using System.Net.Http;
 using System.Net.Http.Json;
 using System.Text.Json;
 using ytLive.Models;
+using AppLog = ytLive.Helpers.AppLog;
 
 namespace ytLive.Services;
-
 /// <summary>
 /// Manages YouTube live stream lifecycle — create broadcasts,
 /// bind stream keys, monitor health.
@@ -79,6 +79,51 @@ public class YouTubeStreamService
         return details;
     }
 
+    /// <summary>
+    /// Pushes the creator-editable broadcast fields to YouTube via
+    /// liveBroadcasts.update (part=snippet,status). Valid any time, including
+    /// while live. Returns null on success, otherwise a human-readable error.
+    /// Note: liveBroadcasts.update REPLACES the snippet part, so scheduledStartTime
+    /// is re-sent unchanged from the stored value — omitting it would clear the
+    /// schedule server-side.
+    /// </summary>
+    public async Task<string?> UpdateBroadcast(string broadcastId, BroadcastMetadata meta)
+    {
+        if (!await EnsureToken()) return "not signed in";
+
+        var tags = meta.TagsCsv
+            .Split(',', StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries)
+            .ToList();
+
+        var broadcast = new
+        {
+            id = broadcastId,
+            snippet = new
+            {
+                title = meta.Title,
+                description = meta.Description,
+                tags = tags,
+                // update replaces the whole snippet part; echo the original schedule
+                scheduledStartTime = (meta.ScheduledStartTime ?? DateTime.UtcNow).ToString("o"),
+                categoryId = "22"
+            },
+            status = new
+            {
+                privacyStatus = string.IsNullOrWhiteSpace(meta.Visibility) ? "private" : meta.Visibility.ToLowerInvariant(),
+                selfDeclaredMadeForKids = meta.MadeForKids
+            }
+        };
+
+        _http.DefaultRequestHeaders.Authorization = new("Bearer", _auth.CurrentChannel!.AccessToken);
+        var response = await _http.PutAsJsonAsync(
+            $"{ApiBase}/liveBroadcasts?part=snippet,status", broadcast);
+
+        if (response.IsSuccessStatusCode) return null;
+        var body = await response.Content.ReadAsStringAsync();
+        AppLog.Write($"Broadcast update failed ({(int)response.StatusCode}): {body}");
+        return $"YouTube rejected the update ({(int)response.StatusCode})";
+    }
+
     /// <summary>Returns the channel's reusable stream (TASK 5 design decision 2):
     /// lists existing streams first and reuses the one with cdn.isReusable=true,
     /// creating it with variable resolution/frame rate on first use. Binding to a