feat(registry): introduce oci-layout backend + --registry flag (PR 1/6)

action.yml

@@ -45,6 +45,13 @@ inputs:
  description: 'GitHub token for authenticated registry access'
  required: false
  default: ${{ github.token }}
+ registry:
+ description: >
+ OCI artifact store used to fetch PHP and extension bundles.
+ Defaults to ghcr.io/buildrush. Set to oci-layout:<path> to
+ fetch from a local OCI-layout directory (used by local CI).
+ required: false
+ default: ""
 outputs:
  php-version:
  description: 'The installed PHP version'

cmd/phpup/main.go

@@ -3,6 +3,7 @@ package main
 import (
 	"context"
 	_ "embed"
+	"flag"
 	"fmt"
 	"log"
 	"os"
@@ -29,12 +30,34 @@ import (
 //go:embed bundles.lock
 var embeddedLockfile []byte
 
+// resolveRegistry picks the registry URI with precedence:
+// 1. --registry flag (cliFlag, passed in)
+// 2. INPUT_REGISTRY env var (GitHub Actions input convention)
+// 3. PHPUP_REGISTRY env var (local/CLI convention)
+// 4. default "ghcr.io/buildrush"
+func resolveRegistry(cliFlag string) string {
+	if cliFlag != "" {
+ return cliFlag
+	}
+	if v := os.Getenv("INPUT_REGISTRY"); v != "" {
+ return v
+	}
+	if v := os.Getenv("PHPUP_REGISTRY"); v != "" {
+ return v
+	}
+	return "ghcr.io/buildrush"
+}
+
 func main() {
 	if len(os.Args) > 1 && os.Args[1] == "--version" {
  fmt.Printf("phpup %s (%s) built %s\n", version.Version, version.Commit, version.BuildDate)
  return
 	}
 
+	registryFlag := flag.String("registry", "",
+ "OCI artifact store (e.g., ghcr.io/buildrush or oci-layout:./out/oci-layout). Overrides INPUT_REGISTRY / PHPUP_REGISTRY; defaults to ghcr.io/buildrush.")
+	flag.Parse()
+
 	ctx := context.Background()
 
 	// 1. Parse inputs
@@ -136,7 +159,7 @@ func main() {
 	if token == "" {
  token = os.Getenv("GITHUB_TOKEN")
 	}
-	registry := "ghcr.io/buildrush"
+	registry := resolveRegistry(*registryFlag)
 	client, err := oci.NewClient(registry, token)
 	if err != nil {
  log.Fatalf("create OCI client: %v", err)

cmd/phpup/registry_flag_test.go

@@ -0,0 +1,39 @@
+package main
+
+import "testing"
+
+func TestResolveRegistry_FlagBeatsEnv(t *testing.T) {
+	t.Setenv("INPUT_REGISTRY", "env-input")
+	t.Setenv("PHPUP_REGISTRY", "env-phpup")
+	got := resolveRegistry("flag-value")
+	if got != "flag-value" {
+ t.Errorf("resolveRegistry flag = %q, want flag-value", got)
+	}
+}
+
+func TestResolveRegistry_InputEnvBeatsPhpupEnv(t *testing.T) {
+	t.Setenv("INPUT_REGISTRY", "env-input")
+	t.Setenv("PHPUP_REGISTRY", "env-phpup")
+	got := resolveRegistry("")
+	if got != "env-input" {
+ t.Errorf("resolveRegistry = %q, want env-input", got)
+	}
+}
+
+func TestResolveRegistry_PhpupEnvUsedWhenInputEmpty(t *testing.T) {
+	t.Setenv("INPUT_REGISTRY", "")
+	t.Setenv("PHPUP_REGISTRY", "env-phpup")
+	got := resolveRegistry("")
+	if got != "env-phpup" {
+ t.Errorf("resolveRegistry = %q, want env-phpup", got)
+	}
+}
+
+func TestResolveRegistry_DefaultsToGHCR(t *testing.T) {
+	t.Setenv("INPUT_REGISTRY", "")
+	t.Setenv("PHPUP_REGISTRY", "")
+	got := resolveRegistry("")
+	if got != "ghcr.io/buildrush" {
+ t.Errorf("resolveRegistry = %q, want ghcr.io/buildrush", got)
+	}
+}