Panel: new Providers tab (data-driven from GET /api/providers — labels/accents
from the daemon registry, enable/active/creds from config). z.ai base_url + key,
api_key masked and preserved on save like the HA token.
Daemon: request_provider_switch() lets the panel push an active-provider change
into the live BLE session (same _set_active_provider path as the watch) so it
takes effect now, not on the next 60s poll; _active_session exposes the session
to the panel thread. On-watch cycle groundwork: provnext -> _cycle_provider
(daemon owns the enabled set/order), and pnm/pi/pc pushed in the payload so the
watch's Provider screen can show the name + "1/3".
server.py: ConfigIn gains providers/active_provider/display_order; secrets masked
in _masked; active_provider change notifies the injected _command_sink.
tray wires set_command_sink(request_provider_switch).
Tests: test_server_providers (masking + sink), test_provider_switch (cycle +
offline persist). 106 passed, 2 Linux-only failures (baseline).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>