Add pet status effects

[jquick]

Add status icons for pets!

Self buffs will have timers as that is known
Debuff will just show icons as we do not know the time

There are cases when we will miss a debuff (no effect packet with some mob WS) but this should cover a good amount of them.

[jquick]

This looks pretty good. Did some testing last night on bst and drg.

[Shuu-37]

Looks good! Well-structured PR that follows existing patterns (mirrors debuffhandler nicely). Clean separation between tracking (petbuffhandler) and rendering (display.lua), and the pet target snap fix is a good catch.

A few minor, non-blocking notes:

petbuffhandler.lua:

• GetActiveEffects(): if expiryTime is set but remaining is negative (already expired), the effect stays in petEffects until 300s past expiry. Not a bug since it renders as icon-only via the remaining > 0 check, but slightly wasteful.
• PET_ABILITY_BUFFS table is small (7 entries) so many jug pet self-buffs won't get timers — understood this is a reasonable starting point.

display.lua:

• maxColumns = 6, maxRows = 1 is hardcoded. Fine in practice since pets rarely have more than 3-4 simultaneous effects.

pettarget.lua:

• Snap anchor change from bottom to top and the ~= nil fix for falsy-zero are both correct.