Status bar: part lamps (CAN, OBD, IMU, CAM), drawn signal and battery icons

WiFi and LTE show signal in four steps with Android's traffic arrows; the battery is
filled to its level in good (charging), caution (under 40 %) or alarm (under 20 %).
OBD, IMU and CAM are lamps by CAN's rule; CAM reads orin-status' new cam_up and vision_up.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

lib/README.md

@@ -29,7 +29,8 @@ pirate-station-aide's (main views, then the rarely used ones grouped as Tools).
 | `AccelGraph` | `widgets/accel_graph.dart` | G-meter: a dot for lateral/longitudinal g, a trace and a peak marker over a window | smart-serow |
 | `GpsCompass` | `widgets/gps_compass.dart` | Heading arrow and bearing; "ACQ" while acquiring, "N/A" without | smart-serow, from gps-speedo |
 | `LinkChip`, `LinkDetails` | `widgets/link_status.dart` | The link's state in good / caution / alarm; address, last-message age, clock offset, USB link | Yukart |
-| `StatusBar` | `widgets/status_bar.dart` | The Orin like a phone's status bar, over every view: link, then hot temperature, CAN, OBD (while connected), GNSS fix and satellites, LTE, WiFi, UPS; and the dark/bright button | Yukart |
+| `StatusBar` | `widgets/status_bar.dart` | The Orin like a phone's status bar, over every view: link; hot temperature; CAN, OBD, IMU, CAM lamps; GNSS fix and satellites; LTE and WiFi signal with traffic arrows; UPS battery; the dark/bright button | Yukart |
+| `BatteryIcon`, `SignalIcon`, `TrafficArrows` | `widgets/status_icons.dart` | The status bar's drawn icons: a battery filled to its level in a role colour, four-step WiFi and cellular signal, Android's up/down traffic pair | Yukart |
 | `MockBanner` | `widgets/mock_banner.dart` | "MOCK DATA — NOT FROM THE CAR" in caution, over every page while the gateway is mocking | Yukart |
 
 ## Conventions