WinDbg plugin, ProcessMemoryWindows, dialog cleanup, and misc fixes

- Add WinDbgMemory plugin with debug server connection support
- Replace ProcessMemory plugin with Windows-specific ProcessMemoryWindows
- Simplify WinDbg dialog: single panel, no tabs, palette-based theming
- Fix example text visibility on dark themes (QPalette::Dark -> Disabled WindowText)
- Fix "file" -> "File" capitalization in source menu
- Add windbg_provider and com_security tests

tests/test_theme.cpp

@@ -92,9 +92,16 @@ private slots:
     void themeManagerHasBuiltIns() {
         auto& tm = ThemeManager::instance();
         auto all = tm.themes();
-        QVERIFY(all.size() >= 2);
+        QVERIFY(all.size() >= 3);
         QCOMPARE(all[0].name, QString("Reclass Dark"));
-        QCOMPARE(all[1].name, QString("Warm"));
+        // VS2022 Dark and Warm are also loaded (order depends on filename sort)
+        bool hasVs = false, hasWarm = false;
+        for (const auto& t : all) {
+            if (t.name == "VS2022 Dark") hasVs = true;
+            if (t.name == "Warm") hasWarm = true;
+        }
+        QVERIFY(hasVs);
+        QVERIFY(hasWarm);
     }
 
     void themeManagerSwitch() {