Widescreen: keep original size, extend view horizontally; fix player/camera

- Default render size is 768 high and as wide as the monitor aspect
  (1835x768 on 3440x1440), scaled up: everything keeps the size players
  know and the view only grows sideways. Height=0 keeps native 1:1.
- Ground: 818/888 clip limits, screen centre floats and integer
  immediates, ground quad list (capped at 1749) moved with the tile list.
- 3D: cGranny ortho (+-512 x +-384, incl. HUD items) scaled; inverse
  projection 0x623a20 (1/1024, 1/768) follows the render size, which fixes
  the camera following the player ("outside world") and the missing
  player / ESC menu.
- tools: game-input.ps1 + autotest-load.ps1 drive the game (load the first
  save game, screenshots in-game and with the ESC menu).

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

tools/game-input.ps1

@@ -0,0 +1,63 @@
+# Drive the game for automated tests: start it, click, press keys, take
+# screenshots. Dot-source it:  . .\tools\game-input.ps1
+#
+#   Start-Sacred                      # launcher, returns the sacred.exe process
+#   Click-At 1720 779                 # screen pixels (left click)
+#   Press-Key 0x1B                    # virtual key (ESC)
+#   Save-Screen screenshots\x.png     # primary monitor area of the game
+#   Stop-Sacred $game                 # only the given process
+#
+# Input goes to the foreground window: don't touch mouse/keyboard meanwhile.
+
+Add-Type -AssemblyName System.Drawing
+Add-Type -Namespace SacredRe -Name Input -MemberDefinition @'
+[DllImport("user32.dll")] public static extern bool SetCursorPos(int x, int y);
+[DllImport("user32.dll")] public static extern void mouse_event(uint flags, uint dx, uint dy, uint data, System.UIntPtr extra);
+[DllImport("user32.dll")] public static extern void keybd_event(byte vk, byte scan, uint flags, System.UIntPtr extra);
+[DllImport("user32.dll")] public static extern bool SetForegroundWindow(System.IntPtr window);
+'@
+
+$script:Root = Split-Path $PSScriptRoot
+
+function Start-Sacred([string]$Arguments = "log", [int]$WaitSeconds = 18) {
+    if (Get-Process sacred -ErrorAction SilentlyContinue) { throw "sacred.exe is already running" }
+    $null = Start-Process (Join-Path $script:Root "build\x86-debug\sacred_re.exe") -ArgumentList $Arguments
+    Start-Sleep $WaitSeconds
+    $game = Get-Process sacred -ErrorAction SilentlyContinue | Select-Object -First 1
+    if (-not $game) { throw "sacred.exe did not start (or crashed)" }
+    [SacredRe.Input]::SetForegroundWindow($game.MainWindowHandle) | Out-Null
+    $game
+}
+
+function Stop-Sacred($Game) {
+    if ($Game -and -not $Game.HasExited) {
+        Stop-Process -Id $Game.Id -Force
+        $Game.WaitForExit(10000) | Out-Null
+    }
+}
+
+function Click-At([int]$X, [int]$Y, [int]$AfterMs = 800) {
+    [SacredRe.Input]::SetCursorPos($X, $Y) | Out-Null
+    Start-Sleep -Milliseconds 150
+    [SacredRe.Input]::mouse_event(0x0002, 0, 0, 0, [UIntPtr]::Zero)  # left down
+    Start-Sleep -Milliseconds 80
+    [SacredRe.Input]::mouse_event(0x0004, 0, 0, 0, [UIntPtr]::Zero)  # left up
+    Start-Sleep -Milliseconds $AfterMs
+}
+
+function Press-Key([byte]$VirtualKey, [int]$AfterMs = 800) {
+    [SacredRe.Input]::keybd_event($VirtualKey, 0, 0, [UIntPtr]::Zero)
+    Start-Sleep -Milliseconds 80
+    [SacredRe.Input]::keybd_event($VirtualKey, 0, 2, [UIntPtr]::Zero)  # key up
+    Start-Sleep -Milliseconds $AfterMs
+}
+
+function Save-Screen([string]$Path, [int]$Width = 3440, [int]$Height = 1440) {
+    $bitmap = New-Object System.Drawing.Bitmap $Width, $Height
+    $graphics = [System.Drawing.Graphics]::FromImage($bitmap)
+    $graphics.CopyFromScreen(0, 0, 0, 0, $bitmap.Size)
+    $full = if ([IO.Path]::IsPathRooted($Path)) { $Path } else { Join-Path $script:Root $Path }
+    $bitmap.Save($full)
+    $graphics.Dispose(); $bitmap.Dispose()
+    $full
+}