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/format.cpp

@@ -267,6 +267,30 @@ static QString readValueImpl(const Node& node, const Provider& prov,
     }
     case NodeKind::Pointer64: {
         uint64_t val = prov.readU64(addr);
+        // Primitive pointer: dereference and show target value
+        // (hex/ptr/fnptr targets fall through to plain void* display)
+        if (node.ptrDepth > 0 && isValidPrimitivePtrTarget(node.elementKind) && val != 0) {
+            uint64_t target = val;
+            for (int d = 1; d < node.ptrDepth && target != 0; d++)
+                target = prov.isReadable(target, 8) ? prov.readU64(target) : 0;
+            if (target != 0 && prov.isReadable(target, sizeForKind(node.elementKind))) {
+                // Create a temporary node of the target kind to format the value
+                Node tmp;
+                tmp.kind = node.elementKind;
+                tmp.strLen = node.strLen;
+                QString derefVal = readValueImpl(tmp, prov, target, 0, mode);
+                if (display) {
+                    QString arrow = QStringLiteral("-> ");
+                    QString sym = prov.getSymbol(val);
+                    if (!sym.isEmpty())
+                        return arrow + derefVal + QStringLiteral("  // ") + sym;
+                    return arrow + derefVal;
+                }
+                return derefVal;
+            }
+            if (!display) return rawHex(val, 16);
+            return fmtPointer64(val);
+        }
         if (!display) return rawHex(val, 16);
         QString s = fmtPointer64(val);
         QString sym = prov.getSymbol(val);