Update FOX_40 IO config to match revised Luckfox Pico Max schematic

[3rdIteration]

Motivation

• The Luckfox Pico Max (FOX_40 / luckfox_40) schematic was revised and the repository's hardware pin mappings needed to reflect the new wiring for display control lines and button pins.
• Keeping src/seedsigner/hardware/io_config.json and docs/io_config.md consistent is required by project guidelines for accurate runtime behavior and documentation.

Description

• Remapped the FOX_40 display control lines in src/seedsigner/hardware/io_config.json to dc -> ["/dev/gpiochip2", 8], rst -> ["/dev/gpiochip1", 24], and bl -> ["/dev/gpiochip1", 25].
• Updated FOX_40 button GPIO assignments in src/seedsigner/hardware/io_config.json to KEY_UP -> ["/dev/gpiochip2", 9], KEY_DOWN -> ["/dev/gpiochip1", 28], KEY_LEFT -> ["/dev/gpiochip1", 19], KEY_RIGHT -> ["/dev/gpiochip1", 20], KEY_PRESS -> ["/dev/gpiochip1", 27], KEY1 -> ["/dev/gpiochip1", 23], KEY2 -> ["/dev/gpiochip1", 22], and KEY3 -> ["/dev/gpiochip1", 21].
• Synchronized the FOX_40 summary row in docs/io_config.md to match the JSON changes.
• Updated tests/test_io_config_profiles.py expected values for the FOX_40 profile so automated tests reflect the new mapping.

Testing

• Ran python -m json.tool src/seedsigner/hardware/io_config.json to validate JSON formatting and it completed without error.
• Executed pytest -q tests/test_io_config_profiles.py and the test suite passed (all profile tests succeeded).

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Codex Task

[Copilot]

Pull request overview

Updates the Luckfox Pico Max (FOX_40 / luckfox_40) hardware profile pin mappings to align runtime GPIO behavior and documentation with the revised schematic.

Changes:

• Remapped FOX_40 display control GPIOs (dc, rst, bl) in io_config.json.
• Remapped FOX_40 button GPIO assignments in io_config.json.
• Updated documentation and unit tests to match the new FOX_40 mappings.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
src/seedsigner/hardware/io_config.json	Updates the FOX_40 display and button GPIO mappings to the revised schematic pins.
docs/io_config.md	Syncs the FOX_40 summary row to reflect the updated JSON mappings.
tests/test_io_config_profiles.py	Updates expected FOX_40 pin mappings so profile tests validate the new configuration.