fix: validate formatting with the selected Go toolchain

Signed-off-by: rldyourmnd <danil@nddev.it.com>

Author: rldyourmnd

core/workspace/device.go

@@ -173,12 +173,12 @@ func ResolvePlacement(
 	}
 	if len(matches) == 0 {
 		return Placement{
-				DeviceID: descriptor.Device.ID, RepositoryID: anchor.Repository.ID,
-				Mode: descriptor.Materialization.DefaultMode,
-			}, []domain.Finding{workspaceFinding(
-				"GDS_WORKSPACE_PLACEMENT_NOT_SELECTED",
-				"Repository does not match a device materialization assignment.", anchor.Repository.ID,
-			)}
+			DeviceID: descriptor.Device.ID, RepositoryID: anchor.Repository.ID,
+			Mode: descriptor.Materialization.DefaultMode,
+		}, []domain.Finding{workspaceFinding(
+			"GDS_WORKSPACE_PLACEMENT_NOT_SELECTED",
+			"Repository does not match a device materialization assignment.", anchor.Repository.ID,
+		)}
 	}
 	if len(matches) != 1 {
 		return Placement{}, []domain.Finding{workspaceFinding(

scripts/validate_go_core.sh

@@ -67,7 +67,10 @@ fi
 BUILD_DIR=$(mktemp -d "${TMPDIR:-/tmp}/gds-build.XXXXXX")
 trap 'rm -rf -- "$BUILD_DIR"' EXIT INT TERM
 
-UNFORMATTED=$(gofmt -l core schemas/embed.go)
+# GOTOOLCHAIN selects `go`, but does not replace a separate `gofmt` on PATH.
+# Use the formatter shipped with the exact toolchain this gate just verified.
+GOFMT="$(go env GOROOT)/bin/gofmt"
+UNFORMATTED=$("$GOFMT" -l core schemas/embed.go)
 if [ -n "$UNFORMATTED" ]; then
   printf 'gofmt required for:\n%s\n' "$UNFORMATTED" >&2
   exit 2