Colour the sliders of playing media players, covers and numbers (0.2.60)

Since firmware 0.2.42 a slider showed the tile's colour only while
Tile::active() held, which is never true for a playing, paused or idle
media player, a cover or a number, so their volume, position and value
sliders stayed grey like a light that is off.

Tile::slider_active() follows Home Assistant's tile sliders instead: grey
for an unavailable entity, a light or fan that is off and a media player
that is off or in standby; a closed cover keeps its colour as in HA's
cover position feature, and a number with a value is active. The sliders
of direct controls on wide tiles and the small sliders use it;
Tile::active() and its other uses are unchanged.

Checked with 282 Python and 15 C++ tests, generate_packages --check, ESP32
builds of both check profiles and host renders of both boards.
Firmware 0.2.52.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

screen_manager/CHANGELOG.md

@@ -1,3 +1,10 @@
+## 0.2.60 (firmware 0.2.52)
+
+Sliders keep their colour while a speaker plays or a blind is open.
+
+- **Coloured sliders for speakers, blinds and numbers.** Since 0.2.42 the volume slider of a playing speaker, the position slider of a blind or curtain and the slider of a number were grey, the colour of a light that is off. Sliders now follow Home Assistant's tile sliders: a speaker that plays, is paused or is idle shows its volume in blue, a cover its position in purple, also when it is closed, and a number its value in teal. A speaker that is off or in standby, and a light or fan that is off, stay grey. This goes for the sliders on double-width tiles and for the small sliders on single tiles.
+- Needs firmware 0.2.52: press **Update** on the screen.
+
 ## 0.2.59 (firmware 0.2.51)
 
 A history card you can read: axes, an hour, a day or a week, and the value under your finger.