Stop secret cooldown errors from remaining action-bar broadcasts

[dfrisone]

What does this PR do?

Stops the remaining action-bar broadcaster events while cooldowns are secret. The existing full-to-press-and-hold fallback still permits ACTIONBAR_SLOT_CHANGED and PLAYER_ENTERING_WORLD to reach Blizzard's cooldown update path under addon taint, producing repeated secret-value SetCooldown errors. The guard now selects off for both active broadcaster modes.

This ports the runtime behavior of the user-confirmed actionbar-secret-cooldown test ZIP (original commit 0569cb3) onto current main. One file only; no new settings, APIs, timers, or polling.

How was it tested?

• User confirmed the original ZIP fixed the reported cooldown error in game. Exact client build and test coverage were not recorded.
• Extracted action-bar source matches original commit 0569cb3 after line-ending normalization. Full file compiles under Lua 5.1; diff-scoped style gate and git diff --check pass.
• Draft: unresolved Evoker regression risk. Turning off the press-and-hold subset also removes native-button initialization events. Standard-bar empower keys still use native bindings; EUI's attribute reassertion updates its own buttons. Reloading or changing slots/talents in restricted content could leave native pressAndHoldAction stale. This is a source-review risk, not a reproduced client failure, and has not been fixed.
• Before ready for review: test Evoker keyboard hold-and-release with Press and Hold Casting off, after restricted-content reload, slot/talent changes, and queued casts; compare mouse casts. Recheck original errors plus extra-action and vehicle cooldowns. Re-enabling tainted cooldown dispatch or switching to the previously problematic queued click path is not a verified solution.
• Distribution ZIP was separately cleaned of repository metadata, with all retained files byte-identical. No ZIP or packaging changes are included in this source PR.

Screenshots

N/A: no intended visual change. No new in-game captures supplied.

Checklist

• New settings default OFF (no behavior change without opt-in) - N/A: existing error-path correction; no setting added.
• Zero cost while disabled: no events registered, no polling, no hooks doing work, no frames built - no new registrations, hooks or frames; changes an existing guard.
• Cheap while enabled: event-driven (no polling, no timer-based logic, no per-frame allocations) - same existing predicate call; removes event dispatch under secrecy.
• No writes onto Blizzard-owned frames (weak-table pattern used); HookScript/hooksecurefunc only, never SetScript on Blizzard frames - existing broadcaster registration changes operate on Blizzard-owned frames; this patch extends when they are unregistered. No new custom frame fields or script replacement, but full taint/regression acceptance remains unverified.
• Tested in-game on live; no version gates or pre-Midnight APIs added - original error fix confirmed by user; exact build/live status and Evoker regression coverage unverified. No new APIs or version gates; Midnight 12.1+ scope retained.