add support for 'button' conditional (#3)

* add support for 'button' conditional

* Route [button] through Multi, add [nobutton], register as static

- [button] now reads conditionals.button via Multi(...) instead of indexing
  _groups.button[1].values[1] directly, so OR/AND lists and repeated groups
  behave like every other argument conditional. [button:1/2] now matches left
  or right; previously only the first value was ever checked and the rest were
  silently dropped. This also removes the unguarded _groups reach-in, which
  Multi itself defends against (it checks _groups is present and falls back to
  _operators).

- Adds [nobutton:N] via NegatedMulti, following the convention that every
  conditional ships its negation (nomod, nostance, nokeydown, ...).

- Bare [button] / [nobutton] now mean "any / no mapped mouse button held",
  mirroring bare [mod]. Bare [nobutton] doubles as an "activated by a keybind
  rather than a click" test.

- Registers button/nobutton in STATIC_CONDITIONALS next to mod and keydown, so
  they are checked once up front rather than re-evaluated for every candidate
  unit during multiscan target scanning.

Still open: IsMouseButtonDown reports live physical state, so a keybound macro
has no button held and [button:N] is false for it, and whether the button still
reads down at macro-execution time depends on whether the action button fires on
mouse-down or mouse-up. Needs in-game verification.

---------

Co-authored-by: Brues <5278969+brues-code@users.noreply.github.com>

Utility.lua

@@ -656,6 +656,24 @@ function CleveRoids.PrintT(t, depth)
     end
 end
 
+CleveRoids.buttons = {
+    ['1'] = 'LeftButton',
+    ['2'] = 'RightButton',
+    ['3'] = 'MiddleButton',
+    ['4'] = 'Button4',
+    ['5'] = 'Button5',
+}
+
+-- True while any mapped mouse button is held. Backs the argument-less [button] /
+-- [nobutton], mirroring how a bare [mod] means "any modifier". Bare [nobutton] is
+-- the practical "activated by a keybind, not a click" test.
+function CleveRoids.AnyMouseButtonDown()
+    for _, name in pairs(CleveRoids.buttons) do
+        if IsMouseButtonDown(name) then return true end
+    end
+    return false
+end
+
 CleveRoids.kmods = {
     ctrl   = IsControlKeyDown,
     lctrl  = IsLeftControlKeyDown,