feat: ctask last command to resume most recently updated workspace

Scans non-archived workspaces, finds highest updated_at, delegates to resume flow with session hooks.

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

cmd/last.go

@@ -0,0 +1,58 @@
+package cmd
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/spf13/cobra"
+	"github.com/warrenronsiek/ctask/internal/config"
+	"github.com/warrenronsiek/ctask/internal/workspace"
+)
+
+var lastCmd = &cobra.Command{
+	Use:          "last",
+	Short:        "Resume the most recently updated workspace",
+	Args:         cobra.NoArgs,
+	SilenceUsage: true,
+	RunE:         runLast,
+}
+
+var (
+	lastShell bool
+	lastAgent string
+)
+
+func init() {
+	lastCmd.Flags().BoolVar(&lastShell, "shell", false, "Open shell instead of agent")
+	lastCmd.Flags().StringVarP(&lastAgent, "agent", "a", "", "Override agent command")
+	rootCmd.AddCommand(lastCmd)
+}
+
+func runLast(cmd *cobra.Command, args []string) error {
+	root := config.ResolveRoot()
+
+	// Scan all non-archived workspaces and find the most recently updated
+	results, err := workspace.ListWorkspaces(root, workspace.ListOpts{
+		IncludeArchived: false,
+		Limit:           0,
+	})
+	if err != nil {
+		return err
+	}
+
+	if len(results) == 0 {
+		fmt.Fprintln(os.Stderr, "No active workspaces found.")
+		os.Exit(1)
+	}
+
+	// Find the one with the most recent updated_at
+	best := results[0]
+	for _, r := range results[1:] {
+		if r.Meta.UpdatedAt.After(best.Meta.UpdatedAt) {
+			best = r
+		}
+	}
+
+	// Delegate to resume logic using the slug
+	return doResume(best.Meta.Slug, false, lastShell, lastAgent)
+}