Smooth graphs, sun path card, skeleton page switches and editor drag & drop

Firmware 0.2.15: trend graphs use a Catmull-Rom curve with a soft fill
drawn by the card's draw event; sun.sun gets a wide sun-path card with
horizon, arc and the sun at its current position; page switches show
the new page's card frames immediately and fill them from a one-shot
timer; the navigation is one full-width bar without a divider; the CYD
adopts the Guition light palette in styles and overlays.

App 0.2.13: pointer-based drag & drop (mouse and touch) to reorder tiles
in the mockup and to drop entities from the list, sticky save bar, a new
header with explained actions and a three-step guide, clearer firmware
dialog. New sun, weather and clock tiles start wide in their best view.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

diagnostics/send_layout.py

@@ -23,7 +23,7 @@ def demo_layout():
         {'entity': 'sensor.demo_temperatuur', 'name': 'Woonkamer', 'options': {'display': 'graph'}},
         {'entity': 'person.demo', 'name': 'Max', 'options': {}},
         {'entity': 'timer.demo', 'name': 'Eieren', 'options': {}},
-        {'entity': 'sun.sun', 'name': 'Zon', 'options': {}},
+        {'entity': 'sun.sun', 'name': 'Zon', 'options': {'display': 'sunpath'}},
         {'entity': 'sensor.demo_energie', 'name': 'Verbruik vandaag', 'options': {'display': 'graph', 'size': 'wide'}},
         {'entity': 'light.demo', 'name': 'Tafellamp', 'options': {'display': 'watch', 'size': 'wide'}},
         {'entity': 'weather.demo_standaard', 'name': 'Weer nu', 'options': {}},