Add Swift/Metal SL(2,C) LCT spatial visualizer for visionOS

.gitignore

@@ -8,14 +8,22 @@ __pycache__/
 *.pyd
 *.egg-info/
 build/
+.build/
 dist/
+swift/**/.build/
+swift/**/DerivedData/
+swift/**/.derivedData/
+swift/**/*.xcuserstate
 # The interactive paper's Sites adapter is source, not a generated build.
 !site/build/
 !site/build/sites-vite-plugin.ts
 extern/
 records/
 # Paper figures are intentional artifacts (the user's global ignore excludes *.png).
 !paper/figures/*.png
+!paper/baylearn/*.png
+# The compiled abstract is a build artifact; rebuild with tectonic (see paper/baylearn/README.md).
+paper/baylearn/*.pdf
 
 # Agent scaffolding (not package content)
 .claude/

Package.swift

@@ -0,0 +1,39 @@
+// swift-tools-version: 6.0
+
+import PackageDescription
+
+// The root manifest makes the Swift library consumable directly from this Git
+// repository. The nested manifest remains convenient for focused development.
+let package = Package(
+  name: "LCTSpatial",
+  platforms: [
+    .macOS(.v15),
+    .visionOS(.v2),
+  ],
+  products: [
+    .library(name: "LCTSpatial", targets: ["LCTSpatial"]),
+    .library(name: "LCTSpatialMetal", targets: ["LCTSpatialMetal"]),
+  ],
+  targets: [
+    .target(
+      name: "LCTSpatial",
+      path: "swift/LCTSpatial/Sources/LCTSpatial"
+    ),
+    .target(
+      name: "LCTSpatialMetal",
+      dependencies: ["LCTSpatial"],
+      path: "swift/LCTSpatial/Sources/LCTSpatialMetal",
+      resources: [.process("Shaders")]
+    ),
+    .testTarget(
+      name: "LCTSpatialTests",
+      dependencies: ["LCTSpatial"],
+      path: "swift/LCTSpatial/Tests/LCTSpatialTests"
+    ),
+    .testTarget(
+      name: "LCTSpatialMetalTests",
+      dependencies: ["LCTSpatial", "LCTSpatialMetal"],
+      path: "swift/LCTSpatial/Tests/LCTSpatialMetalTests"
+    ),
+  ]
+)

README.md

@@ -34,6 +34,22 @@ The finite-dimensional tradeoff is explicit:
 - `normalization="compositional"` favors behavior that tracks matrix
   composition more closely
 
+## Vision Pro spatial atlas
+
+The repository is also a Swift package and includes a simulator-ready visionOS
+instrument under [`swift/LCTVision`](swift/LCTVision). It is designed for fast
+visual intuition-building: scrub `a`, `b`, `c`, or `d` on four complex planes,
+while an automatically selected dependent coefficient keeps `ad - bc = 1`.
+
+Two views update together without conflating their meaning:
+
+- a Metal-updated canonical mesh preview for immediate geometric feedback;
+- a phase-colored sampled complex field produced by the actual separable LCT.
+
+Add the repository as a Swift Package dependency to use the dimension-agnostic
+`LCTSpatial` core or the `LCTSpatialMetal` GPU implementation. The standalone
+package and API guide also live at [`swift/LCTSpatial`](swift/LCTSpatial).
+
 ## Install
 
 The current public release is