Refactor: Use getChurchtoolsBaseUrl() in URL builder functions

[bwl21]

Task

Replace the duplicated base URL logic in churchtools.ts with the centralized getChurchtoolsBaseUrl() function.

Files to Update

• src/services/churchtools.ts:
  • Line 197-202: getGroupUrl() function
  • Line 207-211: getAppointmentUrl() function

Current Pattern (Duplication)

const churchtoolsBaseUrl = import.meta.env.DEV
  ? import.meta.env.VITE_BASE_URL
  : window.location.origin

New Pattern (Centralized)

const churchtoolsBaseUrl = getChurchtoolsBaseUrl()

Why

• Avoids code duplication
• Ensures consistency across the codebase
• Makes maintenance easier (change once, applies everywhere)
• Already documented in AGENTS.md

Related

• New function added in: src/services/churchtools.ts (line 7-9)
• See: AGENTS.md Base URL Pattern section