Prepare CLI loading for ConfigKit configuration

docs/roadmap/implementation.md

@@ -416,6 +416,8 @@ with no CLI activation or example migration.
 
 ## Stage 8 — Prepare Shared CLI Loading And Diagnostics
 
+**Status:** Completed 2026-09-13.
+
 **Goal:** Make one command-facing configuration entry point ready for cutover.
 
 **Work:**

internal/cli/configkit_load.go

@@ -0,0 +1,37 @@
+package cli
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"os"
+
+	configkit "gitea.maximumdirect.net/eric/ConfigKit"
+	"gitea.maximumdirect.net/eric/notarius/internal/core/config"
+)
+
+func loadConfigKit(configPath, profile string, overrides []configkit.Override, opts Options) (*config.LoadedConfig, string, error) {
+	path, err := discoverConfigPath(configPath, opts)
+	if err != nil {
+		return nil, "", err
+	}
+	workingDirectory, err := os.Getwd()
+	if err != nil {
+		return nil, "", fmt.Errorf("determine invocation directory: %w", err)
+	}
+	loaded, err := config.Load(path, config.LoadOptions{Profile: profile, Overrides: overrides, InvocationDirectory: workingDirectory})
+	if err != nil {
+		return nil, "", err
+	}
+	return loaded, path, nil
+}
+
+func writeConfigLoadError(output io.Writer, err error) {
+	var loadError *configkit.LoadError
+	if errors.As(err, &loadError) {
+		if writeErr := configkit.WriteDiagnostics(output, loadError.Diagnostics()); writeErr == nil {
+			return
+		}
+	}
+	fmt.Fprintf(output, "notarius: %v\n", err)
+}

internal/cli/configkit_load_test.go

@@ -0,0 +1,52 @@
+package cli
+
+import (
+	"bytes"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	configkit "gitea.maximumdirect.net/eric/ConfigKit"
+)
+
+func TestLoadConfigKitUsesDiscoveryProfileAndOverrides(t *testing.T) {
+	t.Parallel()
+	root := t.TempDir()
+	path := filepath.Join(root, "notarius.yml")
+	writeConfigKitFile(t, path, "version: 5\npipelines:\n  base:\n    input: {module: input}\n")
+	profiles := filepath.Join(root, "profiles")
+	writeConfigKitFile(t, filepath.Join(profiles, "development.yml"), "pipelines:\n  profiled:\n    input: {module: input}\n")
+	loaded, gotPath, err := loadConfigKit(path, "development", []configkit.Override{{Path: configkit.Keys("output", "directory"), Value: "generated", Flag: "--output"}}, commandContractOptions(t))
+	if err != nil {
+		t.Fatalf("loadConfigKit() error = %v", err)
+	}
+	if gotPath != path || loaded.Config.Pipelines["profiled"].Input.Module != "input" || loaded.Config.Output.Directory == "generated" {
+		t.Fatalf("loaded = %#v, path=%q", loaded.Config, gotPath)
+	}
+}
+
+func TestWriteConfigLoadErrorUsesSafeDiagnostics(t *testing.T) {
+	t.Parallel()
+	path := filepath.Join(t.TempDir(), "invalid.yml")
+	writeConfigKitFile(t, path, "version: 4\n")
+	_, _, err := loadConfigKit(path, "", nil, commandContractOptions(t))
+	if err == nil {
+		t.Fatal("loadConfigKit() error = nil")
+	}
+	var output bytes.Buffer
+	writeConfigLoadError(&output, err)
+	if !strings.Contains(output.String(), "version") || strings.Contains(output.String(), "notarius: configkit") {
+		t.Fatalf("diagnostics = %q", output.String())
+	}
+}
+
+func writeConfigKitFile(t *testing.T, path, contents string) {
+	t.Helper()
+	if err := os.MkdirAll(filepath.Dir(path), 0o700); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.WriteFile(path, []byte(contents), 0o600); err != nil {
+		t.Fatal(err)
+	}
+}

internal/core/config/loaded_config.go

@@ -53,6 +53,12 @@ func loadConfig(path string, options LoadOptions) (*LoadedConfig, error) {
 	return newLoadedConfig(result)
 }
 
+// Load reads a version 5 configuration file into runtime configuration and a
+// private inspection snapshot.
+func Load(path string, options LoadOptions) (*LoadedConfig, error) {
+	return loadConfig(path, options)
+}
+
 func loadConfigSource(source configkit.Source, options LoadOptions) (*LoadedConfig, error) {
 	result, err := loadDocumentSource(source, options)
 	if err != nil {