Add spellbook, fix WMO floor clipping, and polish UI/visuals

- Add spellbook screen (P key) with Spell.dbc name lookup and action bar assignment
- Default Attack and Hearthstone spells available in single player
- Fix WMO floor clipping (gryphon roost) by tightening ceiling rejection threshold
- Darken ocean water, increase wave motion and opacity
- Add M2 model distance fade-in to prevent pop-in
- Reposition chat window, add slash/enter key focus
- Remove debug key commands (keep only F1 perf HUD, N minimap)
- Performance: return chat history by const ref, use deque for O(1) pop_front

src/ui/spellbook_screen.cpp

@@ -0,0 +1,195 @@
+#include "ui/spellbook_screen.hpp"
+#include "core/input.hpp"
+#include "core/application.hpp"
+#include "pipeline/asset_manager.hpp"
+#include "pipeline/dbc_loader.hpp"
+#include "core/logger.hpp"
+#include <algorithm>
+
+namespace wowee { namespace ui {
+
+void SpellbookScreen::loadSpellDBC(pipeline::AssetManager* assetManager) {
+    if (dbcLoadAttempted) return;
+    dbcLoadAttempted = true;
+
+    if (!assetManager || !assetManager->isInitialized()) return;
+
+    auto dbc = assetManager->loadDBC("Spell.dbc");
+    if (!dbc || !dbc->isLoaded()) {
+        LOG_WARNING("Spellbook: Could not load Spell.dbc");
+        return;
+    }
+
+    // WoW 3.3.5a Spell.dbc: field 0 = SpellID, field 136 = SpellName_enUS
+    // Validate field count to determine name field index
+    uint32_t fieldCount = dbc->getFieldCount();
+    uint32_t nameField = 136;
+
+    if (fieldCount < 137) {
+        LOG_WARNING("Spellbook: Spell.dbc has ", fieldCount, " fields, expected 234+");
+        // Try a heuristic: for smaller DBCs, name might be elsewhere
+        if (fieldCount > 10) {
+            nameField = fieldCount > 140 ? 136 : 1;
+        } else {
+            return;
+        }
+    }
+
+    uint32_t count = dbc->getRecordCount();
+    for (uint32_t i = 0; i < count; ++i) {
+        uint32_t spellId = dbc->getUInt32(i, 0);
+        std::string name = dbc->getString(i, nameField);
+        if (!name.empty() && spellId > 0) {
+            spellNames[spellId] = name;
+        }
+    }
+
+    dbcLoaded = true;
+    LOG_INFO("Spellbook: Loaded ", spellNames.size(), " spell names from Spell.dbc");
+}
+
+std::string SpellbookScreen::getSpellName(uint32_t spellId) const {
+    auto it = spellNames.find(spellId);
+    if (it != spellNames.end()) {
+        return it->second;
+    }
+    char buf[32];
+    snprintf(buf, sizeof(buf), "Spell #%u", spellId);
+    return buf;
+}
+
+void SpellbookScreen::render(game::GameHandler& gameHandler, pipeline::AssetManager* assetManager) {
+    // P key toggle (edge-triggered)
+    bool uiWantsKeyboard = ImGui::GetIO().WantCaptureKeyboard;
+    bool pDown = !uiWantsKeyboard && core::Input::getInstance().isKeyPressed(SDL_SCANCODE_P);
+    if (pDown && !pKeyWasDown) {
+        open = !open;
+    }
+    pKeyWasDown = pDown;
+
+    if (!open) return;
+
+    // Lazy-load Spell.dbc on first open
+    if (!dbcLoadAttempted) {
+        loadSpellDBC(assetManager);
+    }
+
+    auto* window = core::Application::getInstance().getWindow();
+    float screenW = window ? static_cast<float>(window->getWidth()) : 1280.0f;
+    float screenH = window ? static_cast<float>(window->getHeight()) : 720.0f;
+
+    float bookW = 340.0f;
+    float bookH = std::min(500.0f, screenH - 120.0f);
+    float bookX = screenW - bookW - 10.0f;
+    float bookY = 80.0f;
+
+    ImGui::SetNextWindowPos(ImVec2(bookX, bookY), ImGuiCond_FirstUseEver);
+    ImGui::SetNextWindowSize(ImVec2(bookW, bookH), ImGuiCond_FirstUseEver);
+
+    bool windowOpen = open;
+    if (ImGui::Begin("Spellbook", &windowOpen)) {
+        const auto& spells = gameHandler.getKnownSpells();
+
+        if (spells.empty()) {
+            ImGui::TextDisabled("No spells known.");
+        } else {
+            ImGui::Text("%zu spells known", spells.size());
+            ImGui::Separator();
+
+            // Action bar assignment mode indicator
+            if (assigningSlot >= 0) {
+                ImGui::TextColored(ImVec4(1.0f, 1.0f, 0.3f, 1.0f),
+                    "Click a spell to assign to slot %d", assigningSlot + 1);
+                if (ImGui::SmallButton("Cancel")) {
+                    assigningSlot = -1;
+                }
+                ImGui::Separator();
+            }
+
+            // Spell list
+            ImGui::BeginChild("SpellList", ImVec2(0, -60), true);
+
+            for (uint32_t spellId : spells) {
+                ImGui::PushID(static_cast<int>(spellId));
+
+                std::string name = getSpellName(spellId);
+                float cd = gameHandler.getSpellCooldown(spellId);
+                bool onCooldown = cd > 0.0f;
+
+                // Color based on state
+                if (onCooldown) {
+                    ImGui::PushStyleColor(ImGuiCol_Text, ImVec4(0.5f, 0.5f, 0.5f, 1.0f));
+                }
+
+                // Spell entry - clickable
+                char label[256];
+                if (onCooldown) {
+                    snprintf(label, sizeof(label), "%s  (%.1fs)", name.c_str(), cd);
+                } else {
+                    snprintf(label, sizeof(label), "%s", name.c_str());
+                }
+
+                if (ImGui::Selectable(label, false, ImGuiSelectableFlags_AllowDoubleClick)) {
+                    if (assigningSlot >= 0) {
+                        // Assign to action bar slot
+                        gameHandler.setActionBarSlot(assigningSlot,
+                            game::ActionBarSlot::SPELL, spellId);
+                        assigningSlot = -1;
+                    } else if (ImGui::IsMouseDoubleClicked(0)) {
+                        // Double-click to cast
+                        uint64_t target = gameHandler.hasTarget() ? gameHandler.getTargetGuid() : 0;
+                        gameHandler.castSpell(spellId, target);
+                    }
+                }
+
+                // Tooltip with spell ID
+                if (ImGui::IsItemHovered()) {
+                    ImGui::BeginTooltip();
+                    ImGui::Text("%s", name.c_str());
+                    ImGui::TextDisabled("Spell ID: %u", spellId);
+                    if (!onCooldown) {
+                        ImGui::TextDisabled("Double-click to cast");
+                        ImGui::TextDisabled("Use action bar buttons below to assign");
+                    }
+                    ImGui::EndTooltip();
+                }
+
+                if (onCooldown) {
+                    ImGui::PopStyleColor();
+                }
+
+                ImGui::PopID();
+            }
+
+            ImGui::EndChild();
+
+            // Action bar quick-assign buttons
+            ImGui::Separator();
+            ImGui::Text("Assign to:");
+            ImGui::SameLine();
+            static const char* slotLabels[] = {"1","2","3","4","5","6","7","8","9","0","-","="};
+            for (int i = 0; i < 12; ++i) {
+                if (i > 0) ImGui::SameLine(0, 2);
+                ImGui::PushID(100 + i);
+                bool isAssigning = (assigningSlot == i);
+                if (isAssigning) {
+                    ImGui::PushStyleColor(ImGuiCol_Button, ImVec4(0.8f, 0.6f, 0.2f, 1.0f));
+                }
+                if (ImGui::SmallButton(slotLabels[i])) {
+                    assigningSlot = isAssigning ? -1 : i;
+                }
+                if (isAssigning) {
+                    ImGui::PopStyleColor();
+                }
+                ImGui::PopID();
+            }
+        }
+    }
+    ImGui::End();
+
+    if (!windowOpen) {
+        open = false;
+    }
+}
+
+}} // namespace wowee::ui