feat: dashboard-style telemetry output

Replace line-by-line telemetry dump with in-place dashboard showing:
- Status indicator (LIVE/STALE/NO SIGNAL)
- LINK: RSSI1, RSSI2, LQ, SNR, power, mode with color coding
- BATT: voltage, current, capacity, percentage
- IMU: pitch, roll, yaw in degrees
- MODE: flight mode name
- Frame counts footer

Add ATTITUDE (0x1E) and FLIGHT_MODE (0x21) telemetry parsing.
Dashboard redraws every 100ms with ANSI cursor control.

celrs/crsf_telemetry.c

@@ -55,6 +55,29 @@ int cel_crsf_telemetry_parse(cel_crsf_frame const* frame,
             return 0;
         }
 
+        case CEL_CRSF_TYPE_ATTITUDE: {
+            if (len < 6) return -1;
+            out->type = CEL_TELEM_ATTITUDE;
+            /* Each value is int16 big-endian / 10000.0 = radians */
+            int16_t pitch = (int16_t)((p[0] << 8) | p[1]);
+            int16_t roll  = (int16_t)((p[2] << 8) | p[3]);
+            int16_t yaw   = (int16_t)((p[4] << 8) | p[5]);
+            out->data.attitude.pitch_rad = pitch / 10000.0f;
+            out->data.attitude.roll_rad  = roll / 10000.0f;
+            out->data.attitude.yaw_rad   = yaw / 10000.0f;
+            return 0;
+        }
+
+        case CEL_CRSF_TYPE_FLIGHT_MODE: {
+            if (len == 0) return -1;
+            out->type = CEL_TELEM_FLIGHT_MODE;
+            size_t copy_len = len < sizeof(out->data.flight_mode.name) ? len
+                                                                       : sizeof(out->data.flight_mode.name);
+            memcpy(out->data.flight_mode.name, p, copy_len);
+            out->data.flight_mode.name[copy_len] = 0;
+            return 0;
+        }
+
         default:
             return -1;
     }