fix: round float params to 6 significant digits on file save

[evanofficial]

Fixes #78.

Root cause

MAVLink transmits parameters as 32-bit single-precision floats. When the Electron main process receives them and stores them as JavaScript number (64-bit double), the conversion introduces floating-point noise:

ATC_RAT_PIT_P,0.18000000715255737   ← ArduDeck (before)
ATC_RAT_PIT_P,0.18                  ← MissionPlanner / mavproxy

The bug is on this line in PARAM_SAVE_FILE:

params.map(p => `${p.id},${p.value}`)

p.value is the raw double with noise.

Fix

Add a formatValue helper that applies toPrecision(6) (6 significant digits — the reliable precision of a 32-bit float) then parseFloat to strip trailing zeros:

const formatValue = (value: number): string => {
  if (Number.isInteger(value)) return String(value);
  return String(parseFloat(value.toPrecision(6)));
};

Before → After examples:

Raw value	Before	After
0.18000000715255737	0.18000000715255737	0.18
0.8999999761581421	0.8999999761581421	0.9
0.004000000189989805	0.004000000189989805	0.004
0.5	0.5	0.5
0	0	0

Test plan

• Save parameters to file and confirm values match MissionPlanner output
• Load the saved file back — values should round-trip correctly
• npx tsc --noEmit passes
• npx eslint . passes

---

I have read and agree to the ArduDeck Contributor License Agreement (CLA.md).

[rubenCodeforges]

Im gonna get drunk to celebrate the first community PR !
@evanofficial Thank you very much , i already mentioned that we are currently on code freeze because ALPHA30 is in testing.

And ill check your pr tomorrow when im back at the HQ.

[evanofficial]

Hey @rubenCodeforges , thanks for the warm welcome! Honored to be the first community PR . No worries on the timeline, totally understand — take your time with the review. I'll be here if you need any changes or have feedback. Looking forward to it!

[rubenCodeforges]

Looks good to me , we will probably squeeze it in the Alpha 30 , @evanofficial great job , thank you !

[evanofficial]

Looks good to me , we will probably squeeze it in the Alpha 30 , @evanofficial great job , thank you !

Thanks! glad to help out, excited to see it land in alpha 30