[Feature]: Add __iter__() method to LayoutElements and Elements for native iteration support

Description

Both LayoutElements (in layoutelement.py) and Elements (in elements.py )are structured to behave like containers or array-like objects. They expose methods like .slice() and hold list/array-like data (texts, element_coords, etc.).

However, neither class implements the __iter__() method. Attempting to loop over them directly results in:

TypeError: 'LayoutElements' object is not iterable

or similarly for Elements.

Suggested Fix

Add the following to both classes:

def __iter__(self):
    return self.iter_elements()

This will enable intuitive usage like:

for el in layout_elements:
    ...

or:

for el in elements:
    ...

Motivation

This change improves the developer experience and aligns both LayoutElements and Elements with Python's collection protocol. It supports clean and readable code, especially when using list comprehensions or loops.

Benefits

• ✅ Enables native iteration with for el in elements:
• ✅ Enhances clarity and developer-friendliness
• 🚫 No breaking changes (backward-compatible)

Start by reading LayoutElements in layoutelement.py and Elements in elements.py, focusing on their existing iter_elements() methods and array-like data. Add native iteration for both classes, then verify that direct loops over LayoutElements and Elements behave as described.