Show who is at the door: camera images on the Guition (0.2.66)

An alert from esp_screens_show_alert takes a `camera` (a camera.* or image.* entity): a Guition with firmware
0.2.57 shows that moment's picture across the top of the card, and a tap opens the camera full screen. A camera
or image tile opens the same full-screen view, refreshed every four seconds at a steady pace.

ESP Screen Manager fetches the snapshot with its own access, sizes it for the screen and serves a 24-bit BMP
under a random, short-lived link on port 8098; the screen loads it with ESPHome's online_image and holds no
Home Assistant token. BMP because ESPHome decodes it per chunk, where a full-screen JPEG held the loop 0.6 s.
The CYD keeps its alerts without the picture and gets no camera tiles.

The Guition also builds with ESPHome 2026.8+ again: backlight_fade.h derived from ESPHome's LEDC output, which
2026.8 made final, so the backlight now dims through ESPHome's own light transition.

Tested on the bench boards and a local add-on on the Home Assistant Yellow; docs/TEST_RESULTS_0266.md.

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

tools/render_topbar.py

@@ -23,7 +23,7 @@ WORK = ROOT / '.esphome' / 'render-topbar'
 PROFILES = {'guition': 'guition-4848s040.yaml', 'cyd': 'home-like-2432s028.yaml'}
 FONTS = ('headline', 'time_label', 'sublabel_big', 'label', 'materialdesign_icons', 'materialdesign_icons_mini')
 # Hardware headers the host cannot compile; the top bar needs none of them.
-SKIP = {'backlight_fade.h', 'guition_diagnostics.h', '__pycache__'}
+SKIP = {'guition_diagnostics.h', '__pycache__'}
 # Header band per board: page width and height above the tiles.
 BANDS = {'guition': (480, 72), 'cyd': (320, 40)}