Extract common UserContext and authentication logic from cancel.zig and
status.zig into new utils/auth.zig module. Add CommonFlags struct to
utils/flags.zig for shared CLI flags. Add getWebSocketUrl() helper to
Config to eliminate URL construction duplication.
Changes:
- Create cli/src/utils/auth.zig with UserContext and authenticateUser()
- Create cli/src/utils/flags.zig with CommonFlags struct
- Update cancel.zig and status.zig to use shared modules
- Add getWebSocketUrl() helper to config.zig
- Export new modules from utils.zig
Reduces code duplication and improves separation of concerns in the
Zig CLI codebase.
