Add distributed communication framework for multi-device tensor parallelism

.gitignore

@@ -92,3 +92,7 @@ iOSInjectionProject/
 
 # VS Code
 .vscode/
+
+# AI agent working directories
+.factory/
+.claude/

Package.swift

@@ -111,10 +111,8 @@ let cmlx = Target.target(
         // vendor docs
         "vendor-README.md",
 
-        // example code + mlx-c distributed
+        // example code
         "mlx-c/examples",
-        "mlx-c/mlx/c/distributed.cpp",
-        "mlx-c/mlx/c/distributed_group.cpp",
 
         // vendored library, include header only
         "json",
@@ -190,15 +188,12 @@ let cmlx = Target.target(
         "mlx/mlx/backend/metal/kernels",
         "mlx/mlx/backend/metal/nojit_kernels.cpp",
 
-        // do not build distributed support (yet)
+        // distributed backends: enable ring + JACCL, disable MPI + NCCL
         "mlx/mlx/distributed/mpi/mpi.cpp",
-        "mlx/mlx/distributed/ring/ring.cpp",
         "mlx/mlx/distributed/nccl/nccl.cpp",
         "mlx/mlx/distributed/nccl/nccl_stub",
-        "mlx/mlx/distributed/jaccl/jaccl.cpp",
-        "mlx/mlx/distributed/jaccl/mesh.cpp",
-        "mlx/mlx/distributed/jaccl/ring.cpp",
-        "mlx/mlx/distributed/jaccl/utils.cpp",
+        "mlx/mlx/distributed/ring/no_ring.cpp",
+        "mlx/mlx/distributed/jaccl/no_jaccl.cpp",
     ],
     cSettings: [
         .headerSearchPath("mlx"),
@@ -302,10 +297,20 @@ let package = Package(
         .testTarget(
             name: "MLXTests",
             dependencies: [
-                "MLX", "MLXNN", "MLXOptimizers",
+                "MLX", "MLXNN", "MLXOptimizers", "DistributedWorker",
             ]
         ),
 
+        // ------
+        // Test support executables
+
+        .executableTarget(
+            name: "DistributedWorker",
+            dependencies: ["MLX", "MLXNN"],
+            path: "Tests/DistributedTestSupport",
+            sources: ["DistributedWorkerMain.swift", "DistributedWorkerOperations.swift"]
+        ),
+
         // ------
         // Example programs