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.

docs/TEST_RESULTS_0255.md

@@ -0,0 +1,60 @@
+# Test results app 0.2.55 / firmware 0.2.47 (2026-09-16)
+
+A light's colour slider on Studio 1 sometimes turned red on release. The chain behind it, all measured
+live on Studio 1 (firmware 0.2.43) and Max's Home Assistant: an automation with a state trigger on the
+six-lamp group `light.studio_1_lights` and no `to:` set `number.studio_1_standby_after` to its current
+value after every colour change. The screen reported it (`esphome.screen_setting`), ESP Screen Manager
+saved the layout and resent layout, header and all 13 tile states, and the screen drew its whole page
+again. While it did, it stopped reading the touch panel. The GT911's stray (0, 0) contact then became
+the finger's last position, and LVGL moved the slider to its end on release. See CHANGELOG 0.2.55 and
+the compatibility note in docs/RELEASING.md.
+
+## Live measurements before the fix (read-only captures)
+
+- 20 colour commits from Studio 1 captured as `call_service` events: 17 carried the colour under the
+  finger. Two were `hs_color [0, 100]` (red) on `light.studio_1_lights` that Max had not chosen, at
+  10:29:07.484 and 10:29:11.132. They left 75 ms and 84 ms after a full resync reached the screen. The
+  third, `[360, 100]` on the ambilight, Max chose on purpose.
+- Every colour change on the lamp group was followed by layout, header and all tile states within
+  0.7 s. On `light.studio_2_ambilight`, which the automation does not watch, only that one tile was sent.
+- The chain reproduced on demand, with Max's permission: `number.set_value` 86400 on
+  `number.studio_1_standby_after` (unchanged) → `esphome.screen_setting` at +0 ms → a dry replica of
+  the add-on logged `sent.pop by server.py:713 run <- server.py:526 save` → the real add-on sent layout,
+  header and 14 states at +341 ms.
+- The colour card does not follow Home Assistant while open (no subscriptions since 0.2.50), so no
+  incoming message can move its knob directly. LVGL 9.5 sets a slider's value from the last touch point
+  on release (`update_knob_pos(obj, false)`), before the card's own RELEASED handler commits it.
+- Earlier Studio 1 logs: a stray (0, 0) was the last sample in 4 of 90 traced edge touches, always just
+  before release (`swipe id=0 st=2 x=0 y=0`, then `st=6 x=0 y=0`).
+
+## Automated
+
+- Python (`.venv-portal`): 214 tests OK. New `tests/test_quiet_resync.py` (5 tests): an unchanged
+  setting event is neither saved nor resent, while a real change and a brightness that lowers the standby
+  brightness are. Every setting number in both profiles and both packages returns before its preference
+  write and event. `layout_changed()` / `refresh_all()` are guarded by the change conditions. The
+  Guition installs the (0, 0) filter and the edge swipe skips it, the CYD does not. Both slider handlers
+  log a jump on release.
+- C++ (`clang++ -std=c++17 -Wall -Wextra -Werror -I. -I components/smart_display`): 14/14 PASS.
+  `tests/test_cyd_ui.cpp` adds `GhostTouch` (a stray sample repeats the previous read, a touch cannot
+  start in the corner, the left edge itself and a rotated corner stay real touches) and `release_jump`.
+- `generate_packages.py --check` green.
+
+## Builds (ESPHome 2026.6.2)
+
+Both Easy Setup profiles, one after the other, from the generated packages with local components:
+
+| Profile | RAM | Flash | vs 0.2.54 |
+|---|---|---|---|
+| easy-guition-device.yaml | 24.0% (78,732 B) | 18.4% (1,496,775 B) | +40 B RAM, +1,468 B flash |
+| easy-cyd-device.yaml | 23.0% (75,484 B) | 76.1% (1,396,799 B) | +16 B RAM, +1,116 B flash |
+
+## Not tested / for the owner
+
+- Hardware. Nothing was flashed. Studio 1 is Max's production screen, and its Wi-Fi password lives only in
+  ESPHome Device Builder, so Max updates it through Home Assistant. On real glass after the update:
+  drag the colour slider of the lamp group several times while the automation runs. Every commit should
+  carry the colour under the finger, the log should show no full resync after a colour change, and it may
+  show `touch: GT911 stray contact at (0,0) ignored`.
+- A host build was not run for this release. The read-callback wrapper and the layout guard were only
+  compiled for the ESP32 boards.