fix(faderpunk): eliminate false fader events from ADC noise (#556)

[ArthurGibert]

Reapplies #556, previously reverted in #626.

Why this was reverted and is coming back now

#556 originally merged directly to main after v1.11.0-beta.1 was already cut, so it skipped the beta test cycle entirely, and its hardware validation checklist was never completed before merge. #626 reverted it so v1.11.0 stable would ship on exactly what beta.1 validated.

This PR reapplies the same change (verified byte-identical to the original #556 diff) so it can go through the process properly this time.

Do not merge until:

• v1.11.0 has fully shipped stable (not just beta — #588 merged, faderpunk/v1.11.0 tagged). ✅ Done.
• The hardware checklist below has actually been completed on real hardware. ✅ Done.
• It can then merge well ahead of the next beta cut, so it rides through a full beta test cycle before reaching stable.

Hardware test checklist

• Load a CV->MIDI layout in Jump takeover mode, patch a trigger/gate cable into an input, set all faders to mid-travel, leave faders untouched: no MIDI CC output / no value changes.
• Fader feel in all three takeover modes (Pickup/Jump/Scale), including slow fades and fast sweeps to the end stops.
• App-level latch takeover feel in Pickup and Scale modes (e.g. after a scene change): pickup engages at the expected proximity, no early/late latching (pickup_tolerance is now 50 LSB).
• CV outputs (e.g. LFO app) still update smoothly (DAC write dedup now in max11300 0.5.3).
• Layer switch (scene button) latching behaves as before.