refactor: remove unused EXTERNAL_ADMIN_TOKEN functionality
- Delete app/services/external_admin_service.py entirely
- Remove EXTERNAL_ADMIN_TOKEN and EXTERNAL_ADMIN_TOKEN_BOT_ID from config
- Remove build_external_admin_token, get_external_admin_token, get_external_admin_bot_id methods
- Remove unused hashlib/hmac imports from config.py
- Remove from system_settings_service: READ_ONLY_KEYS, PLAIN_TEXT_KEYS,
category title, category description, prefix mapping, documentation metadata
- Remove from bot_configuration.py category group
- Remove from main.py startup sequence (ensure_external_admin_token call)
- Remove from .env.example
- Remove from docs/project_structure_reference.md
Fringg
b9b695799c