Migrate to ClassicAPI for macro display, auras and timing

Squash of the classicapi_next branch (10 commits). ClassicAPI is now a hard
requirement, and the Lua-side reimplementations it supersedes are gone:
net -1087 lines across 12 files.

Macro display: resolved macro actions are published through
C_Macro.SetMacroDisplay, so the client draws macro buttons and the
action-bar function overrides this addon used to install are removed.
Ownership is per macro -- ClassicAPI keeps the macros we never claim.

Auras and timing: ClassicAPI is the source of truth for non-player aura
timing via the positional C_UnitAuras.UnitAura, replacing the write-only
buff tracking tables and the overflow-slot fallback.

Cleanup: the hasPfUI76 flag and the pfUI 7.6 branches it gated, two
silently-shadowed code paths, and per-call allocations in the event and
publish paths (SPELL_CAST_EVENT merged). Packaging moves to
brues-code/packager@vCAPI.

Macro syntax: a clause may carry a leading run of [group] blocks sharing
one action, Blizzard-style -- groups are OR'd, first pass wins, and []
always passes. The ;-separated form is unchanged and mixes freely. @focus
clauses with no focus set now fail quietly instead of printing
"Invalid target" on the way past.

Extensions/Tooltip/Generic.lua

@@ -423,7 +423,9 @@ function CleveRoids.IndexActionSlot(slot)
             end
         end
     end
-    CleveRoids.TestForActiveAction(CleveRoids.GetAction(slot))
+    local actions = CleveRoids.GetAction(slot)
+    CleveRoids.TestForActiveAction(actions)
+    CleveRoids.PublishDisplay(actions)
     CleveRoids.SendEventForAction(slot, "ACTIONBAR_SLOT_CHANGED", slot)
 end