Revert "Campaign V slice V4a" - it lost world multisampling

This reverts ceec3bc4. Two independent reasons, either sufficient.

The rendering regression. The slice deleted TextRenderGlStateScope, which
saved GL_MULTISAMPLE and GL_SAMPLE_ALPHA_TO_COVERAGE on entry, disabled them
for the text pass, and restored them on exit (TextRenderGlStateScope.cs:111-112
and 153-154 at the parent commit). Its replacement bakes that state into the
text pipeline but nothing restores it, and GlGpuPassEncoder.Dispose does not
either. Every world renderer is still raw GL at this point in the campaign, so
from the first UI frame onward the world drew with multisampling disabled.

The offline pixel gate caught it: 1,791 of 563,200 compared pixels differed,
0.318% against a 0.001 threshold. The commit message attributed this to
wall-clock-driven ambient animation shifting phase, and committed through the
failure. That explanation does not survive its own control: capturing twice at
the reverted-to commit differs by 19 pixels and twice at the slice's own commit
by 8, while base-versus-head differs by 1,791 - a 224x gap that no shared-noise
source explains. An amplified difference image settles it visually: the changed
pixels are the silhouette edges of every tree, building and rock, with terrain
interiors, water and the entire UI untouched. That is the signature of losing
edge antialiasing, not of animated sprites.

This is the exact failure mode two existing memory notes already warn about -
a mid-frame renderer must set every GL state it uses rather than inherit it,
and issue #52's lesson that a rendering migration must audit per-pass GL state
before declaring itself done.

The scope. The brief was three small leaf renderers plus additive frame-
lifecycle wiring, roughly ten files. The commit changed 334 files with 3,665
insertions and 3,845 deletions, including 323 public-to-internal visibility
conversions across the App assembly, 55 test files, two retired conformance
tests, and a self-described temporary escape hatch for bridging raw-GL viewport
textures. Even without the regression, that is not separable into the part
worth keeping and the part worth dropping.

Reverting rather than patching because the good work here - the RHI frame
lifecycle wiring and a genuine render-state-cache staleness fix - is small
enough to redo cleanly against a tightened spec, while untangling it from 300+
files of unrelated churn is not.

Post-revert: Release build clean, App suite back to 3,843 passed / 3 skipped,
offline pixel gate passing at 19 differing pixels.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/AcDream.App/UI/UiHost.cs

@@ -1,8 +1,8 @@
-using System;
 using System.Collections.Generic;
 using System.Numerics;
 using AcDream.App.Rendering;
 using Silk.NET.Input;
+using Silk.NET.OpenGL;
 
 namespace AcDream.App.UI;
 
@@ -14,7 +14,7 @@ namespace AcDream.App.UI;
 ///
 /// Usage (from <c>GameWindow.OnLoad</c>):
 /// <code>
-///   _uiHost = new UiHost(_gpuDevice, () => _gpuFrameLifetime.Current, _debugFont);
+///   _uiHost = new UiHost(_gl, shadersDir, _debugFont);
 ///   _uiHost.Root.WorldMouseFallThrough += (btn, x, y, f) => HandleWorldClick(btn, x, y);
 ///   _uiHost.Root.WorldKeyFallThrough   += (vk, lp) => HandleHotkey(vk);
 ///
@@ -35,7 +35,7 @@ namespace AcDream.App.UI;
 /// (Keystone root, widget tree). We fuse them into a single host class
 /// because we're not linking to Keystone.
 /// </summary>
-internal sealed class UiHost : System.IDisposable
+public sealed class UiHost : System.IDisposable
 {
     public UiRoot Root { get; } = new();
     public RetailWindowManager WindowManager => Root.WindowManager;
@@ -44,13 +44,12 @@ internal sealed class UiHost : System.IDisposable
 
     /// <summary>The last wired keyboard. Exposed so widgets that need clipboard
     /// access (<see cref="IKeyboard.ClipboardText"/>) or modifier-key state
-    /// (<see cref="IKeyboard.IsKeyPressed"/>) — e.g. <see cref="UiText"/>'s
-    /// Ctrl+C copy — can reach the device. One-keyboard desktop: last wins.</summary>
+    /// (<see cref="IKeyboard.IsKeyPressed"/>) — e.g. <see cref="UiText"/>'s
+    /// Ctrl+C copy — can reach the device. One-keyboard desktop: last wins.</summary>
     public IKeyboard? Keyboard { get; private set; }
 
     private long _startTicks = System.Environment.TickCount64;
     private readonly HostQuiescenceGate _quiescence;
-    private readonly Func<IGpuFrame> _currentFrame;
     private readonly List<IRetainedUiInputBinding> _inputBindings = new();
     private ResourceShutdownTransaction? _inputShutdown;
     private ResourceShutdownTransaction? _shutdown;
@@ -59,24 +58,23 @@ internal sealed class UiHost : System.IDisposable
 
     internal bool IsDisposalComplete => _disposed;
 
-    public UiHost(IGpuDevice device, Func<IGpuFrame> currentFrame, BitmapFont? defaultFont = null)
-        : this(device, currentFrame, defaultFont, new HostQuiescenceGate())
+    public UiHost(GL gl, string shaderDir, BitmapFont? defaultFont = null)
+        : this(gl, shaderDir, defaultFont, new HostQuiescenceGate())
     {
     }
 
     internal UiHost(
-        IGpuDevice device,
-        Func<IGpuFrame> currentFrame,
+        GL gl,
+        string shaderDir,
         BitmapFont? defaultFont,
         HostQuiescenceGate quiescence)
     {
         _quiescence = quiescence ?? throw new ArgumentNullException(nameof(quiescence));
-        _currentFrame = currentFrame ?? throw new ArgumentNullException(nameof(currentFrame));
-        TextRenderer = new TextRenderer(device);
+        TextRenderer = new TextRenderer(gl, shaderDir);
         DefaultFont = defaultFont;
     }
 
-    // ── Per-frame ──────────────────────────────────────────────────────
+    // ── Per-frame ──────────────────────────────────────────────────────
 
     public void Tick(double deltaSeconds)
     {
@@ -92,10 +90,10 @@ internal sealed class UiHost : System.IDisposable
         var ctx = new UiRenderContext(TextRenderer, screenSize, DefaultFont);
         TextRenderer.Begin(screenSize);
         Root.Draw(ctx);
-        TextRenderer.Flush(DefaultFont, _currentFrame());
+        TextRenderer.Flush(DefaultFont);
     }
 
-    // ── Input wiring helpers ───────────────────────────────────────────
+    // ── Input wiring helpers ───────────────────────────────────────────
 
     public void WireMouse(IMouse mouse)
     {
@@ -185,7 +183,7 @@ internal sealed class UiHost : System.IDisposable
         }
     }
 
-    // ── Window manager forwarders (delegate to UiRoot) ─────────────────
+    // ── Window manager forwarders (delegate to UiRoot) ─────────────────
 
     /// <summary>Register a top-level window for Show/Hide/Toggle. See <see cref="UiRoot.RegisterWindow"/>.</summary>
     public RetailWindowHandle RegisterWindow(