Structure asciio object

[nkh]

it's too many entries at the root level of the object

the image below show only half of them

[nkh]

Problem

The main class has grown into a large object with ~50+ attributes handling application lifecycle, rendering, event dispatch, element management, clipboard, and undo/redo.

Refactoring Strategy

Split into 5 focused classes:

• ElementManager - handles @elements, selection state, element queries
• ConnectionManager - manages @connections, connector logic, routing
• UndoManager - encapsulates DO_STACK, DO_STACK_POINTER, snapshot logic
• ClipboardManager - handles copy/paste buffers, serialization
• ActionDispatcher - action registration, shortcut resolution, event routing