refactor(mcp23009e): Migrate menu_navigation example to steami_screen.

[nedseb]

Description

Migrate lib/mcp23009e/examples/menu_navigation.py from direct SSD1327 calls to the steami_screen widget API.

Current state

The example manually renders a menu on the OLED using oled.text() with hand-coded positioning and highlight logic. This is exactly what screen.menu() does.

Proposed change

Replace:

import ssd1327
display = ssd1327.WS_OLED_128X128_SPI(spi, dc, res, cs)
# manual text positioning, highlight rectangles, etc.

With:

from steami_screen import Screen, SSD1327Display
display = SSD1327Display(ssd1327.WS_OLED_128X128_SPI(spi, dc, res, cs))
screen = Screen(display)
screen.menu(items, selected=idx)
screen.show()

Reference

• Current file: lib/mcp23009e/examples/menu_navigation.py
• steami_screen menu widget: screen.menu(items, selected=0)
• Similar migration done for calibrate_magnetometer.py (PR refactor(steami_config): Migrate calibrate_magnetometer to steami_screen UI. #357)