v3 M1b: runtime per-provider theming (firmware) + accent push (daemon)

The watch recolors to the active provider's brand, live, and it's cheap to add
more providers later.

Firmware:
- theme.h: expose THEME_ACCENT_HEX; ui.cpp: COL_ACCENT becomes a runtime
  lv_color_t backed by a shared style (s_accent_style). Static accent widgets
  (launcher tile icons, usage status line, session tokens) attach the shared
  style, so ui_set_theme() recolors them instantly via lv_obj_report_style_change
  — no widget tracking, no recreation.
- ui_set_theme(pv, accent_rgb): swaps the accent + a small logo table keyed by
  provider id (fallback to the Claude mark until a provider ships a logo). Change-
  guarded, so the ~3s payload cadence doesn't churn.
- main.cpp: parse "pv" (id) + "ac" (0xRRGGBB) from the payload and apply.
- Adding a provider needs zero firmware color edits (accent is data-driven) and
  at most one logo-table row.

Daemon: push "ac" = active provider's brand accent alongside "pv".

Test fix: test_providers used asyncio.run(), which closed the suite's shared
event loop and broke every later get_event_loop() test (Py3.13) — mirror the
repo's _run() helper instead.

Verified on the 2.06: forcing an OpenAI-green theme recolored the live launcher
icons (report_style_change path). 216 builds clean; daemon suite 94 passed.

daemon/claude_usage_daemon_windows.py

@@ -915,6 +915,10 @@ async def connect_and_run(device, stop_event: asyncio.Event, tray_state=None) ->
                 auth_problem = status.auth_problem
                 cached = status.to_payload()
                 cached["pv"] = active_pv    # which brand theme the watch wears
+                try:                        # brand accent (0xRRGGBB) for the theme
+                    cached["ac"] = int(provider.accent, 16)
+                except (ValueError, TypeError):
+                    pass
                 last_claude_poll = now
 
             # Now Playing (Phase 5) — best-effort Windows media session, read every