Add UnityExplorer camera/UI diagnostic script

Reflection-based so it compiles across Cinemachine versions. Dumps cameras,
Cinemachine lens FOV, and CanvasScaler settings to identify what drives FOV
and what breaks the HUD at ultrawide.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

tools/unity_diag.cs

@@ -0,0 +1,51 @@
+// UnityExplorer C# console diagnostic — paste into the C# Console tab, hit Run.
+// Dumps cameras, Cinemachine lenses, and UI scalers so we can see what drives FOV
+// and what breaks the HUD at ultrawide. Reflection-based so it compiles regardless
+// of Cinemachine version/namespace (Unity 6 uses Unity.Cinemachine, older uses Cinemachine).
+var sb = new System.Text.StringBuilder();
+
+sb.AppendLine($"SCREEN {UnityEngine.Screen.width}x{UnityEngine.Screen.height} " +
+    $"aspect={(float)UnityEngine.Screen.width / UnityEngine.Screen.height:F4} " +
+    $"full={UnityEngine.Screen.fullScreenMode}");
+
+foreach (var c in UnityEngine.Object.FindObjectsOfType<UnityEngine.Camera>())
+    sb.AppendLine($"CAM  {c.name} depth={c.depth} fov={c.fieldOfView:F2} aspect={c.aspect:F4} " +
+        $"phys={c.usePhysicalProperties} gate={c.gateFit} sensor={c.sensorSize} rect={c.rect} " +
+        $"ortho={c.orthographic} enabled={c.enabled}");
+
+// --- Cinemachine (any version) via reflection ---
+foreach (var mb in UnityEngine.Object.FindObjectsOfType<UnityEngine.MonoBehaviour>())
+{
+    var t = mb.GetType();
+    if (t.FullName == null || t.FullName.IndexOf("Cinemachine", System.StringComparison.OrdinalIgnoreCase) < 0)
+        continue;
+    object lens = null;
+    var bf = System.Reflection.BindingFlags.Public | System.Reflection.BindingFlags.NonPublic |
+             System.Reflection.BindingFlags.Instance;
+    foreach (var name in new[] { "Lens", "m_Lens" })
+    {
+        var p = t.GetProperty(name, bf); if (p != null) { lens = p.GetValue(mb); break; }
+        var f = t.GetField(name, bf);    if (f != null) { lens = f.GetValue(mb); break; }
+    }
+    if (lens != null)
+    {
+        var lt = lens.GetType();
+        object fov = null, mode = null;
+        foreach (var n in new[] { "FieldOfView", "m_FieldOfView" })
+        { var f = lt.GetField(n, bf); if (f != null) { fov = f.GetValue(lens); break; } }
+        foreach (var n in new[] { "ModeOverride", "m_ModeOverride" })
+        { var f = lt.GetField(n, bf); if (f != null) { mode = f.GetValue(lens); break; } }
+        sb.AppendLine($"CM   {t.Name} '{mb.name}' lensFOV={fov} modeOverride={mode} enabled={mb.enabled}");
+    }
+    else sb.AppendLine($"CM   {t.Name} '{mb.name}' (no lens field) enabled={mb.enabled}");
+}
+
+// --- uGUI canvas scalers (HUD scaling at ultrawide) ---
+foreach (var cs in UnityEngine.Object.FindObjectsOfType<UnityEngine.UI.CanvasScaler>())
+    sb.AppendLine($"UI   {cs.name} mode={cs.uiScaleMode} ref={cs.referenceResolution} " +
+        $"match={cs.matchWidthOrHeight} screenMatch={cs.screenMatchMode}");
+
+foreach (var cv in UnityEngine.Object.FindObjectsOfType<UnityEngine.Canvas>())
+    sb.AppendLine($"CANV {cv.name} mode={cv.renderMode} cam={(cv.worldCamera ? cv.worldCamera.name : "none")}");
+
+UnityExplorer.ExplorerCore.Log(sb.ToString());