refactor(ml): drop mlx build tag, fix Taskfile build path

MLX serve backend now auto-enables on darwin/arm64.
Fixed stale cmd/app/main.go reference in Taskfile.

Co-Authored-By: Virgil <virgil@lethean.io>

Taskfile.yaml

@@ -3,4 +3,4 @@ version: '3'
 tasks:
   build:
     cmds:
-      - go build -o build/bin/core cmd/app/main.go
+      - go build -o build/bin/core .

cmd/ml/serve_backend_default.go

@@ -1,8 +1,8 @@
-//go:build !(darwin && arm64 && mlx)
+//go:build !(darwin && arm64)
 
 package ml
 
-import "forge.lthn.ai/core/go/pkg/ml"
+import "forge.lthn.ai/core/go-ai/ml"
 
 func createServeBackend() (ml.Backend, error) {
 	return ml.NewHTTPBackend(apiURL, modelName), nil

cmd/ml/serve_backend_mlx.go

@@ -1,4 +1,4 @@
-//go:build darwin && arm64 && mlx
+//go:build darwin && arm64
 
 package ml
 
@@ -6,7 +6,7 @@ import (
 	"fmt"
 	"log/slog"
 
-	"forge.lthn.ai/core/go/pkg/ml"
+	"forge.lthn.ai/core/go-ai/ml"
 )
 
 func createServeBackend() (ml.Backend, error) {