Current row: moment value with windowed average, stable visibility (#173)

[almothafar]

Follow-up to the #152 fixes, from on-device testing on the Mate 10 Pro. Base is master (#169/#170 merged; branch rebased).

The Current row blinked in and out whenever the instantaneous reading dipped below the 10 mA display floor, and each surface showed its own instant. Maintainer direction: keep the moment value as the headline (no smoothing it away, no show/hide flapping, no "—" placeholder) and show the windowed average alongside.

What it looks like now

Current : −208 mA
          avg: −245 mA      ← second line, 0.8× size, label colour

• The average gets its own smaller, dimmer line under the moment value (the earlier inline (avg: −245) wrapped mid-parenthesis in narrow columns, larger font scales, and Arabic).
• The avg value goes through the same formatCurrentValue as the instant, so sign style, mA unit, and the Western-digit guarantee (Battery details table: fix RTL alignment + use Western digits for numbers #96) can't drift.
• Arabic deliberately keeps the Latin "avg" label (maintainer decision): the line is Latin-heavy already (sign + mA), and a lone Arabic word would break the text direction. Wording may be revisited later.

Behavior

• Average: the same rolling 10-minute window the %/h rate uses (≥ 3 plausible readings over ≥ 45 s, extracted into a shared averagedCurrentMicroAmps helper so rate source A and the displayed average can't disagree). Resets on plug/unplug like the rate; until it's ready the row shows the instant alone.
• Stable visibility: the 10 mA floor gate runs on the average when available, instant-only while the window is fresh. The average moves slowly → the row's presence is stable; a momentary dip no longer hides it, while sustained garbage (pre-calibration Kirin ~1 mA averages) stays hidden as before.
• Notification: mA fallback unchanged (instant only — the line is already long); it inherits the stable gate via hasCurrent.
• BatteryRate gains hasAvgCurrent/avgCurrentMilliAmps; table cells accept CharSequence so the styled value flows through; new string battery_current_avg_line.

Tests

Dip-below-floor stays shown via the avg gate; sustained sub-floor average hidden; fresh window gates on the instant without the avg line; averagedCurrentMicroAmps boundaries (mean, implausible-skip, short span, too few); formatAverageCurrentLine under en + ar. testDebugUnitTest + lintDebug green.

On-device

Watch the Current row through a normal session — it should tick but never blink out, with the avg line appearing ~45 s into a steady window and tracking the sustained draw.

Closes #173

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[almothafar]

Updated after on-device feedback + the #169/#170 merges:

• Rebased onto master (base auto-retargeted; diff is now just the two Current row flickers and disagrees between surfaces — show moment value with windowed average, gate visibility on the average #173 commits).
• Layout reworked: the inline (avg: −245) wrapped mid-parenthesis in narrow columns/larger font scales/Arabic, so the average now renders as its own second line under the moment value, at 0.8× size in the label colour (maintainer's pick from the layout options). String battery_current_value_with_avg replaced by battery_current_avg_line (avg: %1$s / المتوسط: %1$s — Arabic still pending review).

🤖 Generated with Claude Code