refactor: decompose world map into modular component architecture

Break the monolithic 1360-line world_map.cpp into 16 focused modules
under src/rendering/world_map/:

Architecture:
- world_map_facade: public API composing all components (PIMPL)
- world_map_types: Vulkan-free domain types (Zone, ViewLevel, etc.)
- data_repository: DBC zone loading, ZMP pixel map, POI/overlay storage
- coordinate_projection: UV projection, zone/continent lookups
- composite_renderer: Vulkan tile pipeline + off-screen compositing
- exploration_state: server mask + local exploration tracking
- view_state_machine: COSMIC→WORLD→CONTINENT→ZONE navigation
- input_handler: keyboard/mouse input → InputAction mapping
- overlay_renderer: layer-based ImGui overlay system (OCP)
- map_resolver: cross-map navigation (Outland, Northrend, etc.)
- zone_metadata: level ranges and faction data

Overlay layers (each an IOverlayLayer):
- player_marker, party_dot, taxi_node, poi_marker, quest_poi,
  corpse_marker, zone_highlight, coordinate_display, subzone_tooltip

Fixes:
- Player marker no longer bleeds across continents (only shown when
  player is in a zone belonging to the displayed continent)
- Zone hover uses DBC-projected AABB rectangles (restored from
  original working behavior)
- Exploration overlay rendering for zone view subzones

Tests:
- 6 new test files covering coordinate projection, exploration state,
  map resolver, view state machine, zone metadata, and integration

Signed-off-by: Pavel Okhlopkov <pavel.okhlopkov@flant.com>

include/rendering/world_map/layers/coordinate_display.hpp

@@ -0,0 +1,16 @@
+// coordinate_display.hpp — WoW coordinates under cursor on the world map.
+#pragma once
+#include "rendering/world_map/overlay_renderer.hpp"
+
+namespace wowee {
+namespace rendering {
+namespace world_map {
+
+class CoordinateDisplay : public IOverlayLayer {
+public:
+    void render(const LayerContext& ctx) override;
+};
+
+} // namespace world_map
+} // namespace rendering
+} // namespace wowee

include/rendering/world_map/layers/corpse_marker_layer.hpp

@@ -0,0 +1,24 @@
+// corpse_marker_layer.hpp — Death corpse X marker on the world map.
+#pragma once
+#include "rendering/world_map/overlay_renderer.hpp"
+#include <glm/glm.hpp>
+
+namespace wowee {
+namespace rendering {
+namespace world_map {
+
+class CorpseMarkerLayer : public IOverlayLayer {
+public:
+    void setCorpse(bool hasCorpse, glm::vec3 renderPos) {
+        hasCorpse_ = hasCorpse;
+        corpseRenderPos_ = renderPos;
+    }
+    void render(const LayerContext& ctx) override;
+private:
+    bool hasCorpse_ = false;
+    glm::vec3 corpseRenderPos_ = {};
+};
+
+} // namespace world_map
+} // namespace rendering
+} // namespace wowee

include/rendering/world_map/layers/party_dot_layer.hpp

@@ -0,0 +1,21 @@
+// party_dot_layer.hpp — Party member position dots on the world map.
+#pragma once
+#include "rendering/world_map/overlay_renderer.hpp"
+#include "rendering/world_map/world_map_types.hpp"
+#include <vector>
+
+namespace wowee {
+namespace rendering {
+namespace world_map {
+
+class PartyDotLayer : public IOverlayLayer {
+public:
+    void setDots(const std::vector<PartyDot>& dots) { dots_ = &dots; }
+    void render(const LayerContext& ctx) override;
+private:
+    const std::vector<PartyDot>* dots_ = nullptr;
+};
+
+} // namespace world_map
+} // namespace rendering
+} // namespace wowee

include/rendering/world_map/layers/player_marker_layer.hpp

@@ -0,0 +1,16 @@
+// player_marker_layer.hpp — Directional player arrow on the world map.
+#pragma once
+#include "rendering/world_map/overlay_renderer.hpp"
+
+namespace wowee {
+namespace rendering {
+namespace world_map {
+
+class PlayerMarkerLayer : public IOverlayLayer {
+public:
+    void render(const LayerContext& ctx) override;
+};
+
+} // namespace world_map
+} // namespace rendering
+} // namespace wowee

include/rendering/world_map/layers/poi_marker_layer.hpp

@@ -0,0 +1,21 @@
+// poi_marker_layer.hpp — Town/dungeon/capital POI icons on the world map.
+#pragma once
+#include "rendering/world_map/overlay_renderer.hpp"
+#include "rendering/world_map/world_map_types.hpp"
+#include <vector>
+
+namespace wowee {
+namespace rendering {
+namespace world_map {
+
+class POIMarkerLayer : public IOverlayLayer {
+public:
+    void setMarkers(const std::vector<POI>& markers) { markers_ = &markers; }
+    void render(const LayerContext& ctx) override;
+private:
+    const std::vector<POI>* markers_ = nullptr;
+};
+
+} // namespace world_map
+} // namespace rendering
+} // namespace wowee

include/rendering/world_map/layers/quest_poi_layer.hpp

@@ -0,0 +1,21 @@
+// quest_poi_layer.hpp — Quest objective markers on the world map.
+#pragma once
+#include "rendering/world_map/overlay_renderer.hpp"
+#include "rendering/world_map/world_map_types.hpp"
+#include <vector>
+
+namespace wowee {
+namespace rendering {
+namespace world_map {
+
+class QuestPOILayer : public IOverlayLayer {
+public:
+    void setPois(const std::vector<QuestPOI>& pois) { pois_ = &pois; }
+    void render(const LayerContext& ctx) override;
+private:
+    const std::vector<QuestPOI>* pois_ = nullptr;
+};
+
+} // namespace world_map
+} // namespace rendering
+} // namespace wowee

include/rendering/world_map/layers/subzone_tooltip_layer.hpp

@@ -0,0 +1,16 @@
+// subzone_tooltip_layer.hpp — Overlay area hover labels in zone view.
+#pragma once
+#include "rendering/world_map/overlay_renderer.hpp"
+
+namespace wowee {
+namespace rendering {
+namespace world_map {
+
+class SubzoneTooltipLayer : public IOverlayLayer {
+public:
+    void render(const LayerContext& ctx) override;
+};
+
+} // namespace world_map
+} // namespace rendering
+} // namespace wowee

include/rendering/world_map/layers/taxi_node_layer.hpp

@@ -0,0 +1,21 @@
+// taxi_node_layer.hpp — Flight master diamond icons on the world map.
+#pragma once
+#include "rendering/world_map/overlay_renderer.hpp"
+#include "rendering/world_map/world_map_types.hpp"
+#include <vector>
+
+namespace wowee {
+namespace rendering {
+namespace world_map {
+
+class TaxiNodeLayer : public IOverlayLayer {
+public:
+    void setNodes(const std::vector<TaxiNode>& nodes) { nodes_ = &nodes; }
+    void render(const LayerContext& ctx) override;
+private:
+    const std::vector<TaxiNode>* nodes_ = nullptr;
+};
+
+} // namespace world_map
+} // namespace rendering
+} // namespace wowee

include/rendering/world_map/layers/zone_highlight_layer.hpp

@@ -0,0 +1,55 @@
+// zone_highlight_layer.hpp — Continent view zone rectangles + hover effects.
+#pragma once
+#include "rendering/world_map/overlay_renderer.hpp"
+#include "rendering/world_map/zone_metadata.hpp"
+#include "rendering/vk_texture.hpp"
+#include <vulkan/vulkan.h>
+#include <unordered_map>
+#include <memory>
+
+namespace wowee {
+namespace rendering {
+class VkContext;
+}
+namespace pipeline { class AssetManager; }
+namespace rendering {
+namespace world_map {
+
+class ZoneHighlightLayer : public IOverlayLayer {
+public:
+    ~ZoneHighlightLayer() override;
+
+    void setMetadata(const ZoneMetadata* metadata) { metadata_ = metadata; }
+    void initialize(VkContext* ctx, pipeline::AssetManager* am);
+    void clearTextures();
+    void render(const LayerContext& ctx) override;
+    int hoveredZone() const { return hoveredZone_; }
+
+    /// Get the ImGui texture ID for a highlight BLP, loading lazily.
+    /// key is used as cache key; customPath overrides the default path if non-empty.
+    ImTextureID getHighlightTexture(const std::string& key,
+                                     const std::string& customPath = "");
+
+private:
+    /// Load the highlight BLP and register it with ImGui.
+    void ensureHighlight(const std::string& key, const std::string& customPath);
+
+    const ZoneMetadata* metadata_ = nullptr;
+    VkContext* vkCtx_ = nullptr;
+    pipeline::AssetManager* assetManager_ = nullptr;
+
+    struct HighlightEntry {
+        std::unique_ptr<VkTexture> texture;
+        VkDescriptorSet imguiDS = VK_NULL_HANDLE;  // ImGui texture ID
+    };
+    std::unordered_map<std::string, HighlightEntry> highlights_;
+    std::unordered_set<std::string> missingHighlights_;  // areas with no highlight file
+
+    int hoveredZone_ = -1;
+    int prevHoveredZone_ = -1;
+    float hoverHighlightAlpha_ = 0.0f;
+};
+
+} // namespace world_map
+} // namespace rendering
+} // namespace wowee