feat: enhance workspace dock, reorganize menus, fix Reclass Dark theme

- Workspace dock: show member count per type, expandable child rows
  (Type Name format, Hex padding filtered), search/filter box with
  recursive matching, collapsed by default, double-click navigates
  to member in editor
- Menu reorganization: Import/Export submenus, new Tools menu (Type
  Aliases, MCP Server, Options), Data Source moved to View, renamed
  Unload→Close Project, Unsplit→Remove Split, Current Tab Source→
  Data Source
- View menu: add Relative Offsets toggle (persisted, applies to all
  editors and new splits)
- Fix Reclass Dark theme: hover/selected colors were identical to
  background (#1e1e1e), now #2a2a2a/#2a2d2e for visible contrast
- Dim MDI tab text via QPalette::WindowText (Fusion ignores CSS color)
- Remove dead QProxyStyle tab handlers (never called for QMdiArea)

src/editor.h

@@ -61,6 +61,8 @@ public:
         m_disasmProvider = prov; m_disasmRealProv = realProv; m_disasmTree = tree;
     }
 
+    void setRelativeOffsets(bool rel) { m_relativeOffsets = rel; reformatMargins(); }
+
     // Saved sources for quick-switch in source picker
     void setSavedSources(const QVector<SavedSourceDisplay>& sources) { m_savedSourceDisplay = sources; }