Fix: ignore unavailable/unknown flickers in tray trigger (mid-print meter reset)

[andreiz]

Problem

Filament usage can be massively under-counted if the printer/MQTT connection briefly flickers during a print.

The Update Spool automation triggers on any state change of sensor.spoolmansync_<prefix>_active_tray:

triggers:
  - entity_id: sensor.spoolmansync_<prefix>_active_tray
    id: tray
    trigger: state

That sensor’s availability is false when all of a printer's tray sensors are unavailable. So a momentary integration/MQTT hiccup makes active_tray go N -> unavailable -> N and both edges trigger the automation:

• On the unavailable -> N edge, old_tray resolves to -1, so the tray-change branch falls through to its default, which unconditionally resets the usage meter:

  # Reset meter anyway to prevent stale values from accumulating
  - action: utility_meter.calibrate
    target: { entity_id: sensor.spoolmansync_<prefix>_filament_usage_meter }
    data: { value: "0" }

All filament tracked before the blip is discarded. The meter recounts from 0, and the print-end deduction only reflects usage after the flicker.

Real-world example

A 25.58g print flickered once at ~90% progress. The meter (correctly at ~23g) was reset to 0, then only re-accumulated the final ~10%. Spoolman was charged 2.3g for a 25.6g print.

The Tray Change automation already guards against this exact case (trigger.to_state.state not in ['unavailable', 'unknown']); the Update Spool automation's tray trigger does not.

Fix

Add not_from/not_to guards to the tray trigger so transient unavailable/unknown transitions don't run the automation. Applied to both the Bambu and Creality generators.

triggers:
  - entity_id: sensor.spoolmansync_<prefix>_active_tray
    id: tray
    not_from: [unavailable, unknown]
    not_to:   [unavailable, unknown]
    trigger: state

Genuine tray changes (including a real tray -> "no active tray"/empty-string transition) still trigger as before.

Notes

• Users must regenerate their HA config (re-run config generation in the add-on) to pick up the new trigger.