refactor(core): drop unused sudo/app_protection helpers and dead regex chain

Helpers with zero callers anywhere:

- register_sudo_cleanup (3-line trap wrapper in lib/core/sudo.sh)
- will_need_sudo (operation-type dispatcher never consulted)
- _ensure_data_protection_regex (lazy builder for SYSTEM_CRITICAL_FAST_REGEX
  and DATA_PROTECTED_REGEX, two regex vars that nobody read)

With the builder gone, the two empty regex declarations in
lib/core/app_protection.sh and the SYSTEM_CRITICAL_BUNDLES_FAST data array
in lib/core/app_protection_data.sh are also orphans, removed for clean
state. DATA_PROTECTED_BUNDLES stays since it is iterated directly by
should_protect_user_data_path and related protection logic.