Add duty cycle display to repeaters. Closes #308.

frontend/src/components/repeater/RepeaterRadioSettingsPane.tsx

@@ -74,6 +74,11 @@ export function RadioSettingsPane({
           />
           <KvRow label="TX Power" value={data.tx_power != null ? `${data.tx_power} dBm` : '—'} />
           <KvRow label="Airtime Factor" value={data.airtime_factor ?? '—'} />
+          {/* Duty cycle limit is firmware >= 1.15 only; omit the row entirely on
+              older nodes rather than showing an empty placeholder. */}
+          {data.duty_cycle_limit != null && (
+            <KvRow label="Duty Cycle Limit" value={data.duty_cycle_limit} />
+          )}
           <KvRow label="Repeat Mode" value={data.repeat_enabled ?? '—'} />
           <KvRow label="Max Flood Hops" value={data.flood_max ?? '—'} />
         </div>

frontend/src/test/repeaterDashboard.test.tsx

@@ -499,6 +499,7 @@ describe('RepeaterDashboard', () => {
       radio: '910.5250244,62.5,7,5',
       tx_power: '20',
       airtime_factor: '0',
+      duty_cycle_limit: '100.0%',
       repeat_enabled: '1',
       flood_max: '3',
     };

frontend/src/test/useRepeaterDashboard.test.ts

@@ -336,6 +336,7 @@ describe('useRepeaterDashboard', () => {
       radio: null,
       tx_power: null,
       airtime_factor: null,
+      duty_cycle_limit: null,
       repeat_enabled: null,
       flood_max: null,
     });

frontend/src/types.ts

@@ -489,6 +489,9 @@ export interface RepeaterRadioSettingsResponse {
   radio: string | null;
   tx_power: string | null;
   airtime_factor: string | null;
+  // Configured duty-cycle limit (e.g. "25.0%"), firmware-derived from airtime_factor.
+  // Only present on firmware >= 1.15; null on older nodes.
+  duty_cycle_limit: string | null;
   repeat_enabled: string | null;
   flood_max: string | null;
 }