Keep a slider's value when you let go, and stop needless full resends (0.2.55)

A light's colour slider on Studio 1 sometimes sent red on release. Measured
live: an automation with a state trigger on a six-lamp group (no `to:`) set
"Standby after" to its current value after every colour change. The screen
reported the setting, ESP Screen Manager saved the layout and resent layout,
header and every tile state, and the screen drew its whole page again,
reading no touch input meanwhile. The GT911's stray (0, 0) contact then
became the finger's last position, and LVGL 9.5 set the slider from it on
release. Both red commits left 75-85 ms after such a resync.

The app no longer saves or resends a setting event whose value the layout
already has. The four setting numbers return before the preference write
and the event when nothing changed. A layout message that changes nothing
on the screen no longer runs layout_changed() and refresh_all(); the tile
states after it redraw their own tiles. The Guition wraps the LVGL touch
read callback with cyd::GhostTouch, which repeats the previous read for a
pressed (0, 0), and the edge swipe skips that sample too. Both slider
handlers log a jump to an end on release.

Checked with 214 Python and 14 C++ tests, generate_packages --check, and
ESP32 builds of both Easy profiles. Firmware 0.2.47.

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

docs/RELEASING.md

@@ -176,6 +176,36 @@ icons sit off-center in the browser); run `generate_packages.py` afterward.
 The `MDI_GLYPH_*` substitutions are retired: `TILEn_ICON` in manual
 profiles must come from the set. No changed preferences or keys.
 
+### Compatibility 0.2.55 / firmware 0.2.47
+
+App, board profiles and `components/smart_display`. Storage, tile protocol, preferences and keys are unchanged.
+
+- The app: `Manager.run()` compares the validated settings of an `esphome.screen_setting` event with the stored
+  ones and skips `save()` when they are equal. Before, every event saved the layout, `save()` dropped
+  `sent[inbox]`, and the next pass resent layout, header and every tile state.
+- The four setting numbers (`setting_brightness`, `setting_standby_brightness`, `setting_night_brightness`,
+  `setting_standby_seconds`) return before `settings_preference.save` and `setting_event` when
+  `screen_settings::current` did not change (`Settings::operator==`). The Auto standby switch already did.
+  No state is published in that case: `apply_screen_settings` publishes numbers only when they differ.
+- `runtime_tiles::receive`, op `layout`: `layout_changed()` and `refresh_all()` run only for changed or moved
+  tiles, the first layout, a rotation or settings change, or another `pages` count or title. A repeat still
+  sets `inbox`, `keepalive_seconds`, `layout_rev` and `last_received`; the tile states after it redraw their
+  own tiles through `refresh_tile`.
+- Guition `on_boot` wraps the read callback of the LVGL touch input (ESPHome's `LVTouchListener`):
+  `cyd::GhostTouch` repeats the previous read when a pressed read lands exactly on the native (0, 0), mapped
+  with `LvglComponent::rotate_coordinates`, and logs `touch: GT911 stray contact at (0,0) ignored`.
+  `on_update` skips (0, 0) before `touch_guard` and `edge_swipe`. The CYD keeps its own XPT2046 `TouchFilter`.
+- `cyd::release_jump` logs (tag `slider`, WARN) when LVGL's recalculation on release (`update_knob_pos(obj,
+  false)` for RELEASED in LVGL 9.5) moves a dragged slider to an end, more than a quarter of its range away
+  from where it was held: the three colour-card rows and the tile sliders.
+- Measured on Studio 1 (firmware 0.2.43, 2026-09-16): `automation.studio_1_scherm_wakker_houden_bij_licht`, a
+  state trigger on a group of six lamps without `to:`, set `number.studio_1_standby_after` to its current
+  value after every colour change. The resulting `esphome.screen_setting` event triggered a full resync
+  (layout plus 13 states) 0.34 s later. Both red commits (`hs_color [0, 100]`) left 75-85 ms after such a
+  resync reached the screen. Earlier Studio 1 logs show a stray (0, 0) as the last sample in 4 of 90 traced
+  edge touches. ESPHome 2026.6.2's GT911 driver writes 0 to the status register before it reads the
+  coordinates; that ordering is a candidate for an upstream fix.
+
 ### Compatibility 0.2.54 / firmware 0.2.46
 
 Board profiles; the app raises `FIRMWARE_VERSION` and adjusts the Auto standby row of the Claude skill.