Correct Luckfox Pico Pi (FOX_PI) display/button mapping to blue GPIO labels

[3rdIteration]

Motivation

• Fix a mismatch between the Luckfox Pico Pi board diagrams (blue 40-pin GPIO labels) and the runtime mappings so runtime GPIO initialization matches the physical board wiring.
• Keep io_config.json, docs/io_config.md, and unit tests consistent per the repo IO config guidance.

Description

• Updated src/seedsigner/hardware/io_config.json for FOX_PI so display control lines are dc/rst/bl = [59]/[56]/[70] and button mappings are KEY_UP [121,"pull_up"], KEY_DOWN [1,"pull_up"], KEY_LEFT [122,"pull_up"], KEY_RIGHT [0,"pull_up"], KEY_PRESS [52,"pull_up"], KEY1 [145,"pull_up"], KEY2 [123,"pull_up"], KEY3 [55,"pull_up"] to match the blue GPIO labels from the 40-pin diagrams.
• Kept pull-up bias for all button mappings and also ensured FOX_22 and FOX_40 entries use blue-board GPIO numbering with pull-up where appropriate.
• Updated docs/io_config.md and tests/test_io_config_profiles.py to reflect the corrected FOX_PI (and the FOX_22/FOX_40) mappings so documentation and tests remain in sync with runtime config.

Testing

• Validated JSON syntax with python -m json.tool src/seedsigner/hardware/io_config.json, which completed successfully.
• Ran unit tests with pytest -q tests/test_io_config_profiles.py tests/test_luckfox_camera_backend.py, which passed (15 passed).

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Codex Task