New SCREEN_PROVIDER (Menu → "Provider"): shows the active provider's brand name
in the accent colour (recolors live on a theme switch via the shared accent
style) and its "i / c" position among the enabled providers. A Switch button
notifies {"cmd":"provnext"}; the daemon owns the enabled set/order and cycles to
the next one, so the watch stays dumb. When only one provider is enabled the
button is replaced by a hint.
main.cpp parses the optional pnm/pi/pc payload fields into ui_set_provider_badge.
Builds green on all four boards (206/216/18/216_c6); verified on 2.06 hardware
(OpenAI green theme + "2 / 3" + Switch).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
