remove the last duplicate findModuleDef from ShipLayoutPreview

ShipLayoutPreview was the one widget the findFooDef sweep missed: it held a
bare const std::vector<ModuleDef>* rather than a config, so the shared
ModulesConfig::findModuleDef was not a drop-in and the file-local copy
survived. Hold the ModulesConfig instead and call the shared finder.

The sole caller already had the ModulesConfig one dereference away.

Co-Authored-By: Claude <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01YHcUerKAZKWNvSKJxYKbnG

src/ui/ShipLayoutPreview.h

@@ -18,7 +18,7 @@ public:
 
     void setShipAndLayout(const std::vector<std::string>& shipLayout,
                           const ShipLayoutConfig& layout,
-                          const std::vector<ModuleDef>* modules);
+                          const ModulesConfig* modules);
     void clear();
 
     // Shows an empty placeholder box (no ship layout) so the preview stays
@@ -37,7 +37,7 @@ private:
 
     std::vector<std::vector<CellInfo>> m_grid;
     std::vector<PlacedModule> m_placedModules;
-    const std::vector<ModuleDef>* m_modules;
+    const ModulesConfig* m_modules;
     int m_rows;
     int m_cols;
     bool m_placeholder = false;