feat(flash): add 'flash read' subcommand. Added support for latest node APIs.

[chalkers]

Summary

• Add kaluma flash read using size-first strategy: .flash -s then .flash -r.
• Handle CRLF normalization and strip ANSI/console noise during read.
• Options:
  • --stdout: write program to stdout
  • --timestamp (-t): append -YYYYMMDDTHHMMSS or backup-.js in a directory
  • --quiet (-q): suppress progress output
• Node 20/22 support via serialport@^12 and API updates.
• Reliability: grow buffered serial capacity and add timed reads.
• Docs: README/CHANGELOG updated, CLI help examples extended, AGENTS.md added.
• Meta: license aligned to Apache-2.0; add contributor Andrew Chalkley.

Behavior/Compatibility

• No breaking changes; kaluma flash unchanged.
• kaluma flash read requires a destination path or --stdout.

Testing

• Verified on Node 20: kaluma ports, kaluma flash read backup.js, timestamped save, stdout piping.
• Size-first logic works with devices that print logs during transfer.

[chalkers]

Squashed fix into previous commit and force-pushed to feat/flash-read-node20.

• Fix: implement BufferedSerial.readAwaitWithTimeout used by flash read
• Head: 1494a9c
• Sanity: CLI loads locally; Tested flash read and write on-device.

[chalkers]

Summary - Small issue tweak found on another MCU

• Fixes intermittent end-of-transfer timeouts in kaluma flash read .
• Root cause: the read loop requested more bytes than remain (remaining + 10),
  causing a wait for bytes that never arrive when the device returns exactly the
  last chunk.
• Fix: cap each read request to the remaining byte count; keep CRLF normalization and ANSI stripping unchanged.

Reproduction (before)

• node bin/kaluma.js ports to find the port.
• node bin/kaluma.js flash read -p /dev/tty.usbmodem101 ./backup-nes.js
• Observed: progress stops near the end and errors with a timeout.

Validation (after)

• node bin/kaluma.js flash read -p /dev/tty.usbmodem101 backup-nes.js -q
• Result: completes reliably; example output size: 23259 bytes.
• Also verified that backup-nes.js same size.

Notes

• On macOS, SerialPort.list() may not include VID/PID, so the default @2e8a
  lookup can fail. Use an explicit port path from kaluma ports (e.g., /dev/
  tty.usbmodem101).
• Flags: --stdout to stream program to terminal, -t to add a timestamped
  filename, -q to suppress progress dots.

Risk/Impact

• Low. Only read-loop request size changed; file content and normalization
  behavior remain the same.

Should be good to go. I'll do other PR if there's anything big.