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/input_handler.hpp

@@ -0,0 +1,37 @@
+// input_handler.hpp — Input processing for the world map.
+// Extracted from WorldMap::render (Phase 9 of refactoring plan).
+// SRP — input interpretation separated from state changes and rendering.
+#pragma once
+
+#include "rendering/world_map/world_map_types.hpp"
+
+namespace wowee {
+namespace rendering {
+namespace world_map {
+
+enum class InputAction {
+    NONE,
+    CLOSE,
+    ZOOM_IN,
+    ZOOM_OUT,
+    CLICK_ZONE,          // left-click on continent view zone
+    CLICK_COSMIC_REGION, // left-click on cosmic landmass
+    RIGHT_CLICK_BACK,    // right-click to go back
+};
+
+struct InputResult {
+    InputAction action = InputAction::NONE;
+    int targetIdx = -1;  // zone or cosmic region index
+};
+
+class InputHandler {
+public:
+    /// Process input for current frame. Returns the highest-priority action.
+    InputResult process(ViewLevel currentLevel,
+                        int hoveredZoneIdx,
+                        bool cosmicEnabled);
+};
+
+} // namespace world_map
+} // namespace rendering
+} // namespace wowee