Add --json output format

[19bk]

Add a --json flag to the read, dump, and scan commands that outputs results as JSON instead of Rich tables.

This would allow piping into jq or other tools:

modbus read 192.168.1.10 40001 -c 5 --json | jq '.registers[].value'

Suggested JSON schema for read:

{
  "host": "192.168.1.10",
  "type": "holding",
  "slave": 1,
  "registers": [
    {"address": 40001, "raw": 237, "value": "237"}
  ]
}

Good first contribution. The logic is in modbus_cli/cli.py.

[passionworkeer]

One implementation approach that tends to age well is to separate data collection from rendering: have
ead/dump/scan build a structured result object first, then send it either to Rich tables or JSON serialization. That avoids duplicating command logic and makes tests straightforward: assert on the intermediate payload, then add a small snapshot test for --json. I would also keep numeric fields typed in JSON (�ddress,
aw, slave) and only stringify values that are truly display-formatted.

[zakiscoding]

I'd like to work on this! I'll add a \ flag to the , , and \ commands and submit a PR shortly.

[19bk]

Solid advice @passionworkeer — separating data collection from rendering is exactly the right call. That's more or less how it landed in #8: structured result first, then Rich or JSON depending on the flag. Keeps the command logic clean and testable. Appreciate you thinking through the design here.

@zakiscoding shipped this in #8 and it's merged now. Nice work — thanks for jumping on it so fast 🤝