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

CMakeLists.txt

@@ -314,6 +314,11 @@ if(BUILD_TESTING)
     target_link_libraries(test_core PRIVATE ${QT}::Core ${QT}::Test)
     add_test(NAME test_core COMMAND test_core)
 
+    add_executable(test_typeinfer tests/test_typeinfer.cpp)
+    target_include_directories(test_typeinfer PRIVATE src)
+    target_link_libraries(test_typeinfer PRIVATE ${QT}::Core ${QT}::Test)
+    add_test(NAME test_typeinfer COMMAND test_typeinfer)
+
     add_executable(test_format tests/test_format.cpp src/format.cpp src/addressparser.cpp)
     target_include_directories(test_format PRIVATE src)
     target_link_libraries(test_format PRIVATE ${QT}::Core ${QT}::Test)