Adds a memory-mapped keyboard so you can type into the Galaksija. Based on
the libretro Galaksija core's scheme (not guessed): reading 0x2000+offset
returns 0xFE when the key at that matrix offset is held, 0xFF otherwise;
the keyMap gives the offset per key ('A'=1 ... Enter=48, Space=31, etc.).
- galaksija-keyboard.c: drives reads of 0x2000-0x203F from a keys[] table and
exports set_key(offset, down) for the host to push key events. Never drives
outside the keyboard range.
- galaksija-ram.c: ram-64k variant that yields reads of 0x2000-0x203F to the
keyboard (writes still go to RAM), so the two never fight for the bus.
- ChipRuntime: ChipInstance.hasKeyboard + setKey() expose the chip's set_key.
- CustomChipPart: bridges browser keydown/keyup (by KeyboardEvent.code, via
GALAKSIJA_KEY_OFFSET) into the chip, ignoring keystrokes while the code
editor or an input is focused so typing code is never hijacked.
- The gallery example gains the keyboard chip (now 7 chips, 99 wires) and uses
galaksija-ram.
Test chipbus-galaksija-keyboard: pressing 'A' (offset 1) makes the BASIC
monitor echo "A" after its ">" prompt and advances the cursor. 41 chipbus
tests pass.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>