fix: kill Fusion outline on QScintilla, type inference hints, workspace styling

- Suppress PE_Frame on QsciScintilla in MenuBarStyle to eliminate the
  1px dark (#171717) Fusion outline around the editor area
- Add --screenshot flag for automated pixel regression testing
- Add type inference engine (typeinfer.h) with hex pattern analysis
- Show inferred type hints on hex nodes in compose output
- Style workspace tree corner/header widgets to match theme
- Fix integer overflow in compose.cpp array element addressing
- Fix integer overflow in core.h structSpan calculation
- Add bounds check on activePaneIdx in controller
- Use QPointer for deferred dock lambda safety
- Workspace delegate uses icon Normal/Disabled for viewed state

src/editor.h

@@ -37,6 +37,7 @@ public:
     void scrollToNodeId(uint64_t nodeId);
     void showFindBar();
     void dismissHistoryPopup();
+    void dismissAllPopups();
 
     // ── Column span computation ──
     static ColumnSpan typeSpan(const LineMeta& lm, int typeW = kColType);
@@ -155,8 +156,8 @@ private:
     // ── Value history ref (owned by controller) ──
     const QHash<uint64_t, ValueHistory>* m_valueHistory = nullptr;
     QWidget* m_historyPopup = nullptr;  // ValueHistoryPopup (file-local class in editor.cpp)
-    QWidget* m_disasmPopup = nullptr;   // DisasmPopup (file-local class in editor.cpp)
-    QWidget* m_structPreviewPopup = nullptr; // StructPreviewPopup (file-local class in editor.cpp)
+    QWidget* m_disasmPopup = nullptr;        // TitleBodyPopup (file-local class in editor.cpp)
+    QWidget* m_structPreviewPopup = nullptr; // TitleBodyPopup (file-local class in editor.cpp)
     const Provider* m_disasmProvider = nullptr;   // snapshot or real — for reading tree data
     const Provider* m_disasmRealProv = nullptr;   // real process provider — for reading code at arbitrary addresses
     const NodeTree* m_disasmTree = nullptr;