feat: add built-in array comparison

scripts/generate-array-fixture.ps1

@@ -39,3 +39,45 @@ $arrayDefinition = [ordered]@{
 $json = $arrayDefinition | ConvertTo-Json -Depth 8
 [System.IO.File]::WriteAllText($outputPath, $json + [Environment]::NewLine, [System.Text.UTF8Encoding]::new($false))
 Write-Host "Generated $($microphones.Count) microphones: $outputPath"
+
+$spiralOutputPath = Join-Path $projectRoot 'assets/array-geometries/fermat-spiral-192.array.json'
+$spiralMicrophones = [System.Collections.Generic.List[object]]::new()
+$microphoneCount = 192
+$radius = 0.225
+$goldenAngle = [Math]::PI * (3 - [Math]::Sqrt(5))
+
+for ($index = 0; $index -lt $microphoneCount; $index++) {
+    $microphoneRadius = $radius * [Math]::Sqrt(($index + 0.5) / $microphoneCount)
+    $angle = $index * $goldenAngle
+    $x = $microphoneRadius * [Math]::Cos($angle)
+    $y = $microphoneRadius * [Math]::Sin($angle)
+    $spiralMicrophones.Add([ordered]@{
+        id       = 'mic-{0:D3}' -f ($index + 1)
+        position = @([Math]::Round($x, 6), [Math]::Round($y, 6), 0)
+    })
+}
+
+$spiralDefinition = [ordered]@{
+    schemaVersion    = '1.0.0'
+    kind             = 'micarrsim.array'
+    id               = 'fermat-spiral-192'
+    name             = '192-channel Fermat spiral'
+    description      = 'Equal-area Fermat spiral on a 0.45 m circular aperture for comparison with the rectangular baseline'
+    units            = 'm'
+    coordinateSystem = [ordered]@{
+        handedness = 'right'
+        xAxis       = 'right'
+        yAxis       = 'up'
+        zAxis       = 'toward-scene'
+    }
+    aperture         = [ordered]@{ width = 0.45; height = 0.45 }
+    microphones      = $spiralMicrophones
+}
+
+$spiralJson = $spiralDefinition | ConvertTo-Json -Depth 8
+[System.IO.File]::WriteAllText(
+    $spiralOutputPath,
+    $spiralJson + [Environment]::NewLine,
+    [System.Text.UTF8Encoding]::new($false)
+)
+Write-Host "Generated $($spiralMicrophones.Count) microphones: $spiralOutputPath"