Skills, auto-attack, aura and chain lightning rework, Esc, cache fix

- Skill bar: no art selection; slot 0 is the right-click art, keys 0-6 cast
  slots directly; cooldown labels in exact seconds; slot 0 set apart.
- Arts regenerate on their own (casting no longer refills the group).
- Auto-attack after targeting or casting at a hostile creature, at the speed
  of a held button.
- Auras can be recast while active (renew, no second visual).
- Blicke wie Klingen hits every enemy in range, physical, with life leech.
- Blitzschlag steers the game's own chain: 3 + level/5 hits, 1 + level/10
  chains, re-hits a lone enemy.
- Weapon sets: click selects, drag only from the selected set; the leftmost
  set is clickable (signed hit tests).
- Esc closes open windows before opening the game menu.
- HUD: standalone buttons and texts are centred.
- Record cache sized for widened views (town lag while walking).
- Shared game code: orders, fx events, text drawing, cooldowns, effects.

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

src/mods/skillkeys.cpp

@@ -1,24 +1,24 @@
-// Skill keys cast the skill, not only select it.
+// Skill keys cast their combat-art slot.
 //
-// The taskbar's combat-art slots are selected with a key (cUI_Taskbar2::
-// HandleEvent -> SelectSkillSlot 0x6e17d0); the selected art is then used with
-// the right mouse button. When a skill key (src/mods/input.cpp) selects a slot,
-// this mod also presses the right mouse button: a WM_RBUTTONDOWN is posted to
-// the game window, so the game handles it exactly like a real right-click at
-// the cursor (UI hit tests, target under the cursor, cEvent_creature 0x105).
-// The button is released with the key, so holding the key is holding the
-// button. Slots selected by clicking them with the mouse are not cast.
+// The game casts one art with the right mouse button: the one in the
+// "selected" art slot, which is always slot 0 now (src/mods/skillbar.cpp).
+// Slot 0's key presses the right mouse button; the keys of slots 1-6 first
+// make their slot the selected one. The button is pressed by posting
+// WM_RBUTTONDOWN to the game window, so the game handles it exactly like a
+// real right-click at the cursor (UI hit tests, target under the cursor,
+// cEvent_creature 0x105), and released with the key: holding the key is
+// holding the button. While no skill key is held, slot 0 is selected again
+// (checked every engine tick, which also covers saves loaded with another
+// selection).
 
 #include "mods/skillkeys.h"
 
-#include "mods/skillbar.h"
-
-#include <cstdint>
-#include <mutex>
+#include <atomic>
 
 #include <windows.h>
 
-#include "re/hook.h"
+#include "game/engine/events.h"
+#include "mods/skillbar.h"
 
 namespace mods::skillkeys {
 namespace {
@@ -40,77 +40,49 @@ LPARAM CursorClientPos(HWND window) {
     return MAKELPARAM(cursor.x, cursor.y);
 }
 
-// The key that is to cast slot `slot` when it gets selected, then the key
-// holding the right mouse button down. Set on the window thread, used on the
-// thread that handles UI events.
-struct State {
-    std::mutex lock;
-    int pendingKey = 0;
-    unsigned pendingSlot = 0;
-    bool keyDown = false;
-    int heldKey = 0;  // right button is down for this key
-    HWND window = nullptr;
-};
-State g_state;
+// The key holding the right mouse button down, and the window it was pressed
+// in. Set on the window thread, read by the engine tick.
+std::atomic<int> g_heldKey{0};
+HWND g_window = nullptr;
+
+void OnTick(uint8_t*) {
+    if (!g_heldKey.load() && mods::skillbar::SelectedSkillSlot() != 0) {
+        mods::skillbar::SelectSkillSlot(0);
+    }
+}
+
+struct Registration {
+    Registration() { game::OnEngineTick(&OnTick); }
+} g_registration;
 
 } // namespace
 
-void CastOnSelect(unsigned slot, int vk) {
-    std::lock_guard guard(g_state.lock);
-    g_state.pendingKey = vk;
-    g_state.pendingSlot = slot;
-    g_state.keyDown = true;
+void KeyPressed(unsigned slot, int vk) {
+    if (g_heldKey.load() || !mods::skillbar::SkillSlotHasArt(slot)) {
+        return;
+    }
+    HWND window = GameWindow();
+    if (!window) {
+        return;
+    }
+    g_window = window;
+    g_heldKey = vk;  // before selecting: the tick leaves the selection alone
+    if (slot != 0) {
+        mods::skillbar::SelectSkillSlot(slot);
+    }
+    PostMessageW(window, WM_RBUTTONDOWN, MK_RBUTTON, CursorClientPos(window));
+}
+
+bool KeyHeld() {
+    return g_heldKey.load() != 0;
 }
 
 void KeyReleased(int vk) {
-    std::lock_guard guard(g_state.lock);
-    if (g_state.pendingKey == vk) {
-        g_state.keyDown = false;  // released before the slot was selected
-    }
-    if (g_state.heldKey == vk) {
-        g_state.heldKey = 0;
-        PostMessageW(g_state.window, WM_RBUTTONUP, 0, CursorClientPos(g_state.window));
-    }
-}
-
-// After a slot was selected: cast if a skill key asked for it.
-void OnSlotSelected(void* taskbar, unsigned slot) {
-    std::lock_guard guard(g_state.lock);
-    if (!g_state.pendingKey || g_state.pendingSlot != slot) {
+    if (g_heldKey.load() != vk) {
         return;
     }
-    const int key = g_state.pendingKey;
-    g_state.pendingKey = 0;
-    if (!mods::skillbar::HasSkillSlot(taskbar, slot)) {
-        return;  // empty slot: nothing was selected
-    }
-    HWND window = GameWindow();
-    if (!window || g_state.heldKey) {
-        return;
-    }
-    PostMessageW(window, WM_RBUTTONDOWN, MK_RBUTTON, CursorClientPos(window));
-    if (g_state.keyDown) {
-        g_state.heldKey = key;
-        g_state.window = window;
-    } else {
-        PostMessageW(window, WM_RBUTTONUP, 0, CursorClientPos(window));
-    }
+    PostMessageW(g_window, WM_RBUTTONUP, 0, CursorClientPos(g_window));
+    g_heldKey = 0;
 }
 
 } // namespace mods::skillkeys
-
-namespace game {
-
-// cUI_Taskbar2::SelectSkillSlot (0x6e17d0): makes combat-art slot `slot` the
-// right mouse button's art (keys, clicks on the slot).
-void __fastcall UiTaskbar_SelectSkillSlot(void* self, void* edx, unsigned slot, int notify);
-RE_HOOK(0x006e17d0, UiTaskbar_SelectSkillSlot);
-void __fastcall UiTaskbar_SelectSkillSlot(void* self, void* edx, unsigned slot, int notify) {
-    UiTaskbar_SelectSkillSlot_original(self, edx, slot, notify);
-    if (self) {
-        mods::skillkeys::OnSlotSelected(self, slot & 0xffff);
-    }
-}
-
-} // namespace game
-