feat: primitive pointer modifiers, type chooser fixes, double-click to edit

Type chooser:
- Fix PointerTarget mode hiding primitives due to stale modifier state
- Preselect */[n] modifier buttons to reflect current node type
- Primitive pointer support: int32*, double**, etc with provider deref
- hex64*/ptr64* with * modifier falls back to void* (meaningless deref)
- isValidPrimitivePtrTarget guard in controller, compose, format
- Modifier toggle no longer resets list selection
- Primitive pointers open FieldType mode (not PointerTarget)
- Type edit requires double-click (was single-click, too easy to misclick)

Other:
- Custom dock titlebar with themed close button, no float button
- Status bar font synced at startup
- Resize grip reworked as direct MainWindow child, font-independent
- File menu "Source" renamed to "Current Tab Source"

Tests: 41 type_selector, 39 editor, 17 controller (200 total, 0 failures)

src/typeselectorpopup.h

@@ -40,6 +40,7 @@ struct TypeEntry {
 struct TypeSpec {
     QString baseName;
     bool    isPointer  = false;
+    int     ptrDepth   = 0;       // 1 = *, 2 = ** (only meaningful when isPointer)
     int     arrayCount = 0;       // 0 = not array
 };
 
@@ -57,6 +58,7 @@ public:
     void setMode(TypePopupMode mode);
     void applyTheme(const Theme& theme);
     void setCurrentNodeSize(int bytes);
+    void setModifier(int modId, int arrayCount = 0);
     void setTypes(const QVector<TypeEntry>& types, const TypeEntry* current = nullptr);
     void popup(const QPoint& globalPos);