feat: add branch, notification, org, open, whoami commands

Ports five commands from tea that fgj-sid was missing:

- fgj branch {list,rename,delete} — list branches with protection
  status, rename, and delete with confirmation.
- fgj notification {list,read} — list user notifications (unread by
  default, --all for everything), mark individual threads read.
- fgj org {list,create,delete} — manage organizations on the host.
  Create accepts --description/--full-name/--website/--location and
  --visibility (public/limited/private).
- fgj open [number] — open the repo, issue, or PR in a browser.
  Auto-detects issue-vs-PR via GetIssue. Falls back to printing the
  URL when stdout is not a TTY or --url is passed.
- fgj whoami — display authenticated user + host.

All commands follow the established pattern (parseRepo + config.Load +
api.NewClientFromConfig + ios), support --json where list semantics
apply, and share a new loadClient helper for host-scoped (non-repo)
commands. Tested live against forgejo.zerova.net.

Refs audit recommendation.md §'v0.5.0 — Missing resources'.

cmd/whoami.go

@@ -0,0 +1,53 @@
+package cmd
+
+import (
+	"fmt"
+
+	"github.com/spf13/cobra"
+)
+
+var whoamiCmd = &cobra.Command{
+	Use:   "whoami",
+	Short: "Show the authenticated user on the current host",
+	Long:  "Display login, full name, and email for the authenticated user on the active host.",
+	Example: `  # Show who you are on the active host
+  fgj whoami
+
+  # On a specific host
+  fgj whoami --hostname forgejo.example.com
+
+  # As JSON
+  fgj whoami --json`,
+	RunE: runWhoami,
+}
+
+func init() {
+	rootCmd.AddCommand(whoamiCmd)
+	addJSONFlags(whoamiCmd, "Output as JSON")
+}
+
+func runWhoami(cmd *cobra.Command, args []string) error {
+	client, err := loadClient()
+	if err != nil {
+		return err
+	}
+
+	user, _, err := client.GetMyUserInfo()
+	if err != nil {
+		return fmt.Errorf("failed to fetch current user: %w", err)
+	}
+
+	if wantJSON(cmd) {
+		return outputJSON(cmd, user)
+	}
+
+	fmt.Fprintf(ios.Out, "%s\n", user.UserName)
+	if user.FullName != "" && user.FullName != user.UserName {
+		fmt.Fprintf(ios.Out, "  name:  %s\n", user.FullName)
+	}
+	if user.Email != "" {
+		fmt.Fprintf(ios.Out, "  email: %s\n", user.Email)
+	}
+	fmt.Fprintf(ios.Out, "  host:  %s\n", client.Hostname())
+	return nil
+}