Feature request: Customizable agenda scheduled/deadline prefix text

Feature Request

Allow users to customize or remove the "Scheduled:" and "Deadline:" prefix text in the agenda view.

Problem

The repeated "Scheduled:" text adds visual clutter, especially when viewing many items:

Day-agenda for Saturday:
Saturday    08 February 2025
  Work:       09:00 ------------ Scheduled: Team standup
  Work:       10:00 ------------ Scheduled: Code review
  Work:       14:00 ------------ Scheduled: TODO Fix login bug
  Personal:   15:00 ------------ Scheduled: Dentist appointment
  Home:       18:00 ------------ Scheduled: TODO Grocery shopping
  Home:       19:00 ------------ Deadline:  TODO Pay rent

The word "Scheduled" appears 5 times and doesn't add useful information - users already know these are scheduled items because they're in the agenda.

Proposed Solution

With customizable prefixes, users could achieve a cleaner view:

Day-agenda for Saturday:
Saturday    08 February 2025
  Work:       09:00 ------------ Team standup
  Work:       10:00 ------------ Code review
  Work:       14:00 ------------ TODO Fix login bug
  Personal:   15:00 ------------ Dentist appointment
  Home:       18:00 ------------ TODO Grocery shopping
  Home:       19:00 ------------ ! TODO Pay rent

Add configuration options similar to Emacs org-mode:

require('orgmode').setup({
  -- Remove scheduled prefix entirely
  org_agenda_scheduled_leaders = {'', ''},
  -- Keep deadline visible with short prefix
  org_agenda_deadline_leaders = {'! ', '! '},
})

This would give users control over their agenda density while maintaining compatibility with existing behavior as the default.

Thank you for the excellent plugin!

Start by locating the agenda rendering entry point and the setup configuration that controls agenda display. Trace where the “Scheduled:” and “Deadline:” prefixes are assembled, then identify the relevant agenda tests or add coverage for default prefixes, empty prefixes, and custom leader values.