[codex] Add configurable stratagem direction keys

[DrakonWolfDev]

Summary

• add a plugin-wide Direction Keys selector with Arrow keys and WASD keys options
• translate abstract stratagem directions at execution time for both built-in and custom stratagem actions
• keep Arrow keys as the default for backward compatibility with existing installations
• extend the standalone stratagem validator to accept both Arrow and W/A/S/D input
• document the new setting and add unit coverage for both layouts and fallback behavior

Motivation

The plugin currently requires Helldivers 2 directional stratagem inputs to be rebound to the arrow keys. Many keyboard players use the game's standard W/A/S/D directional bindings instead. Making the output layout selectable lets both configurations work without changing the generated stratagem sequences or duplicating action data.

Behavior

The new setting is available under Settings → Plugins → HELLDIVERS 2 → Settings:

• Arrow keys (default): Up/Down/Left/Right emit KEY_UP, KEY_DOWN, KEY_LEFT, and KEY_RIGHT
• WASD keys: Up/Down/Left/Right emit KEY_W, KEY_S, KEY_A, and KEY_D

Saved settings that are missing or contain an unknown layout safely fall back to Arrow keys. This preserves existing behavior after upgrading.

Validation

• python -m unittest -v test_key_mapping.py — 4 tests passed
• python -m py_compile main.py key_mapping.py test_key_mapping.py test_stratagems.py — passed
• python -m update validate — passed with the repository's 8 existing extra-icon warnings

[jslay88]

This is now bundled into the v2.3.0 release (version bump in #20, merged to main).

I've opened a Store update PR to make it available for release: StreamController/StreamController-Store#203

Thanks for the contribution!