RedCraftChat 0.2.6-SNAPSHOT

Translate action bars, both wire forms

The action bar arrives two different ways and they are different packets:
the dedicated SET_ACTION_BAR_TEXT that Adventure's sendActionBar
produces, and system chat with the overlay flag, which is how CMI writes
its. The chat interceptor only ever saw the second, which is why the
elytra speed bar came out translated while the museum's "Use /musehub to
quit" loop and the parkour HUD never did.

ActionBarTranslator handles both, and is deliberately not built on the
chat buffer. Cancelling and holding is what multi-line menus need and
exactly what a surface repainting twenty times a second cannot afford,
so this follows the hologram pattern instead: rewrite in place on the
netty thread when the cache has the answer, pass the original through
and warm the cache when it does not. The first repeat after a miss is
translated; nothing is held or reordered, and no corrective resend,
which would reset the fade timer and double-flash text that corrects
itself one repeat later anyway.

Counters are what make the cache work. NumericTemplate collapses every
frame of a timer onto one template, the template is what gets translated
and cached, and each frame injects its own numbers into the cached
translation. A twenty-hertz HUD costs one provider call ever, and a
frame is never shown carrying a placeholder: the store path refuses
translations that lost one, and the rewrite path refuses output that
still contains one, which covers a provider inventing an extra.

A per-player churn guard counts cache misses, not text changes, so a
cyclic animation stops costing once the cache has seen a full cycle
where a change counter would trip forever. Only new provider spending
goes quiet; cache hits keep rewriting.

Overlay system chat moves out of the interceptor's buffer behind the
same flag, which also stops it paying the grouping delay and a scheduler
hop per frame. translate-action-bars off restores the old behaviour
exactly.

Clients before 1.19.1 are documented as unsupported for this and for
system chat: they receive the legacy chat packet nothing listens for,
and thirty days of logs show no real player below 1.21.5.