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>

src/rendering/world_map/input_handler.cpp

@@ -0,0 +1,57 @@
+// input_handler.cpp — Input processing for the world map.
+// Extracted from WorldMap::render (Phase 9 of refactoring plan).
+#include "rendering/world_map/input_handler.hpp"
+#include "core/input.hpp"
+#include <imgui.h>
+#include <cmath>
+
+namespace wowee {
+namespace rendering {
+namespace world_map {
+
+InputResult InputHandler::process(ViewLevel currentLevel,
+                                   int hoveredZoneIdx,
+                                   bool cosmicEnabled) {
+    InputResult result;
+    auto& input = core::Input::getInstance();
+
+    // ESC closes the map
+    if (input.isKeyJustPressed(SDL_SCANCODE_ESCAPE)) {
+        result.action = InputAction::CLOSE;
+        return result;
+    }
+
+    // Scroll wheel zoom
+    auto& io = ImGui::GetIO();
+    float wheelDelta = io.MouseWheel;
+    if (std::abs(wheelDelta) < 0.001f)
+        wheelDelta = input.getMouseWheelDelta();
+
+    if (wheelDelta > 0.0f) {
+        result.action = InputAction::ZOOM_IN;
+        return result;
+    } else if (wheelDelta < 0.0f) {
+        result.action = InputAction::ZOOM_OUT;
+        return result;
+    }
+
+    // Continent view: left-click on hovered zone (from previous frame)
+    if (currentLevel == ViewLevel::CONTINENT && hoveredZoneIdx >= 0 &&
+        input.isMouseButtonJustPressed(1)) {
+        result.action = InputAction::CLICK_ZONE;
+        result.targetIdx = hoveredZoneIdx;
+        return result;
+    }
+
+    // Right-click to go back (zone → continent; continent → world)
+    if (io.MouseClicked[1]) {
+        result.action = InputAction::RIGHT_CLICK_BACK;
+        return result;
+    }
+
+    return result;
+}
+
+} // namespace world_map
+} // namespace rendering
+} // namespace wowee