feat: add mantle apply command for versioned workflow storage

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: michaelmcnees

internal/cli/apply.go

@@ -0,0 +1,60 @@
+package cli
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/dvflw/mantle/internal/config"
+	"github.com/dvflw/mantle/internal/db"
+	"github.com/dvflw/mantle/internal/workflow"
+	"github.com/spf13/cobra"
+)
+
+func newApplyCommand() *cobra.Command {
+	return &cobra.Command{
+		Use:   "apply <file>",
+		Short: "Apply a workflow definition",
+		Long:  "Validates and stores a workflow definition as a new immutable version in the database.",
+		Args:  cobra.ExactArgs(1),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			filename := args[0]
+
+			cfg := config.FromContext(cmd.Context())
+			if cfg == nil {
+				return fmt.Errorf("config not loaded")
+			}
+
+			database, err := db.Open(cfg.Database.URL)
+			if err != nil {
+				return fmt.Errorf("failed to connect to database: %w", err)
+			}
+			defer database.Close()
+
+			rawContent, err := os.ReadFile(filename)
+			if err != nil {
+				return fmt.Errorf("reading %s: %w", filename, err)
+			}
+
+			result, err := workflow.ParseBytes(rawContent)
+			if err != nil {
+				return fmt.Errorf("parsing %s: %w", filename, err)
+			}
+
+			version, err := workflow.Save(cmd.Context(), database, result, rawContent)
+			if err != nil {
+				return err
+			}
+
+			if version == 0 {
+				latestVersion, _ := workflow.GetLatestVersion(cmd.Context(), database, result.Workflow.Name)
+				fmt.Fprintf(cmd.OutOrStdout(), "No changes — %s is already at version %d\n",
+					result.Workflow.Name, latestVersion)
+			} else {
+				fmt.Fprintf(cmd.OutOrStdout(), "Applied %s version %d\n",
+					result.Workflow.Name, version)
+			}
+
+			return nil
+		},
+	}
+}

internal/cli/root.go

@@ -31,6 +31,7 @@ func NewRootCommand() *cobra.Command {
 	cmd.AddCommand(newInitCommand())
 	cmd.AddCommand(newMigrateCommand())
 	cmd.AddCommand(newValidateCommand())
+	cmd.AddCommand(newApplyCommand())
 
 	return cmd
 }