Self / ally arts cast on the hero when pointed at an enemy

Arts with launch type 2 (buffs, auras, heals) are only valid on allies
or without a target; with an enemy under the cursor the game dropped
the order. Orders of a player hero for such arts lose a non-ally target,
which casts them on the hero. The launch type comes from the art
definition tables (game/engine/arts.h, tools/arttable.mjs).

Also: skill keys check the relocated taskbar slots (all 7), Ghidra
data labels (g_ names in names.txt).

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

src/mods/skillbar.cpp

@@ -83,6 +83,13 @@ void SelectWeaponSet(unsigned slot) {
     }
 }
 
+bool HasSkillSlot(const void* taskbar, unsigned slot) {
+    const auto* p = static_cast<const uint8_t*>(taskbar);
+    constexpr size_t kSlotCount = 0x15c;  // u16: slots shown, from SetSlotCount
+    return slot < kSlots && slot < *reinterpret_cast<const uint16_t*>(p + kSlotCount) &&
+           reinterpret_cast<void* const*>(p + kSkillSlots)[slot] != nullptr;
+}
+
 void OnTaskbar(void* taskbar) {
     g_taskbar = static_cast<uint8_t*>(taskbar);
 }