feat(calendar): add create-calendar command

Create new secondary Google Calendars via the API.

Usage:
  gog calendar create-calendar "My Calendar" --timezone America/New_York

Supports --description, --timezone, --location flags.
Outputs calendar ID and summary in both text and JSON modes.

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

Author: alexknowshtml

internal/cmd/calendar.go

@@ -21,6 +21,7 @@ func newCalendarCmd(flags *rootFlags) *cobra.Command {
 		Short: "Google Calendar",
 	}
 	cmd.AddCommand(newCalendarCalendarsCmd(flags))
+	cmd.AddCommand(newCalendarCreateCalendarCmd(flags))
 	cmd.AddCommand(newCalendarAclCmd(flags))
 	cmd.AddCommand(newCalendarEventsCmd(flags))
 	cmd.AddCommand(newCalendarEventCmd(flags))

internal/cmd/calendar_create_calendar.go

@@ -0,0 +1,72 @@
+package cmd
+
+import (
+	"fmt"
+	"os"
+	"strings"
+
+	"github.com/spf13/cobra"
+	"github.com/steipete/gogcli/internal/outfmt"
+	"github.com/steipete/gogcli/internal/ui"
+	"google.golang.org/api/calendar/v3"
+)
+
+func newCalendarCreateCalendarCmd(flags *rootFlags) *cobra.Command {
+	var description string
+	var timeZone string
+	var location string
+
+	cmd := &cobra.Command{
+		Use:   "create-calendar <name>",
+		Short: "Create a new secondary calendar",
+		Args:  cobra.ExactArgs(1),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			u := ui.FromContext(cmd.Context())
+			account, err := requireAccount(flags)
+			if err != nil {
+				return err
+			}
+
+			name := strings.TrimSpace(args[0])
+			if name == "" {
+				return usage("required: calendar name")
+			}
+
+			svc, err := newCalendarService(cmd.Context(), account)
+			if err != nil {
+				return err
+			}
+
+			cal := &calendar.Calendar{
+				Summary:     name,
+				Description: strings.TrimSpace(description),
+				TimeZone:    strings.TrimSpace(timeZone),
+				Location:    strings.TrimSpace(location),
+			}
+
+			created, err := svc.Calendars.Insert(cal).Context(cmd.Context()).Do()
+			if err != nil {
+				return fmt.Errorf("create calendar: %w", err)
+			}
+
+			if outfmt.IsJSON(cmd.Context()) {
+				return outfmt.WriteJSON(os.Stdout, map[string]any{"calendar": created})
+			}
+
+			u.Out().Printf("id\t%s", created.Id)
+			u.Out().Printf("summary\t%s", created.Summary)
+			if created.TimeZone != "" {
+				u.Out().Printf("timezone\t%s", created.TimeZone)
+			}
+			if created.Description != "" {
+				u.Out().Printf("description\t%s", created.Description)
+			}
+			return nil
+		},
+	}
+
+	cmd.Flags().StringVar(&description, "description", "", "Calendar description")
+	cmd.Flags().StringVar(&timeZone, "timezone", "", "IANA timezone (e.g., America/New_York)")
+	cmd.Flags().StringVar(&location, "location", "", "Calendar location")
+	return cmd
+}