fix(whatsminer): correct inverted is_mining logic across all backends

[ankitgoswami]

Summary

• V1/V2: parse_is_mining was inverted — the btmineroff/mineroff field means "miner is off", so "true" means mining is OFF, but the old code returned true (mining active). Added fallback extraction at /Msg/mineroff for newer firmware responding to the legacy API.
• V3: Had no implementation (trait default always returned true). Now extracts the working field from get.device.info at /msg/miner/working.
• Named intermediate variables (miner_off, working) to match the actual API field names so the inversion logic is self-documenting.

Test plan

• Unit tests for parse_is_mining covering mineroff="true", mineroff="false", and missing field
• Verified against M60SVK40 (V3 backend): pause() → is_mining=false, resume() → is_mining=true
• Verified against M50SVH50 (V2 backend, fw 20240624): pause() → is_mining=false, resume() → is_mining=true
• Verify against a V1-era WhatsMiner

🤖 Generated with Claude Code

[b-rowan]

{
  "STATUS": "S",
  "When": 1773871985,
  "Code": 131,
  "Msg": {
    "mineroff": "false",
    "mineroff_reason": "",
    "mineroff_time": "",
    "FirmwareVersion": "20230803.11.REL",
    "power_mode": "",
    "hash_percent": ""
  },
  "Description": ""
}

From V2 miner. V1 should be the same.

[b-rowan]

{
  "STATUS": "S",
  "When": 1773872028,
  "Code": 131,
  "Msg": {
    "mineroff": "false",
    "mineroff_reason": "",
    "mineroff_time": "",
    "FirmwareVersion": "20240924.14.Rel",
    "power_mode": "normal",
    "power_limit_set": "3300",
    "hash_percent": "0"
  },
  "Description": ""
}

Another firmware version.

[b-rowan]

{
  "STATUS": "S",
  "When": 1773872068,
  "Code": 131,
  "Msg": {
    "mineroff": "false",
    "FirmwareVersion": "20230208.18.Rel",
    "power_mode": "normal",
    "hash_percent": "0"
  },
  "Description": ""
}

Older still. This might be closer to the V1 API.

[b-rowan]

{
  "STATUS": "S",
  "When": 1773872125,
  "Code": 131,
  "Msg": {
    "mineroff": "false",
    "mineroff_reason": "",
    "mineroff_time": "",
    "FirmwareVersion": "20250214.16.1",
    "power_mode": "",
    "power_limit_set": "2147483647",
    "hash_percent": ""
  },
  "Description": ""
}

Here's the result from a V3 device.

[b-rowan]

I'll see if I can confirm V1 results tomorrow, we have some M20s laying around that use 1.4.0

[ankitgoswami]

I left the /SUMMARY/0/btmineroff extraction path in assuming it was for V1

[b-rowan]

I left the /SUMMARY/0/btmineroff extraction path in assuming it was for V1

That's my guess too, but it might be one or the other for V1/V2, I'll know more tomorrow.

[b-rowan]

{
  "STATUS": "S",
  "When": 1773930539,
  "Code": 131,
  "Msg": {
    "btmineroff": "true",
    "Firmware Version": "'20220919.15.REL'"
  },
  "Description": "whatsminer v1.4.0"
}

V1 is in fact the one with btmineroff.