Phase 3

frontend/src/components/settings/SettingsRadioSection.tsx

@@ -43,6 +43,7 @@ export function SettingsRadioSection({
   const [lat, setLat] = useState('');
   const [lon, setLon] = useState('');
   const [txPower, setTxPower] = useState('');
+  const [pathHashMode, setPathHashMode] = useState('0');
   const [freq, setFreq] = useState('');
   const [bw, setBw] = useState('');
   const [sf, setSf] = useState('');
@@ -73,6 +74,7 @@ export function SettingsRadioSection({
     setLat(String(config.lat));
     setLon(String(config.lon));
     setTxPower(String(config.tx_power));
+    setPathHashMode(String(config.path_hash_mode));
     setFreq(String(config.radio.freq));
     setBw(String(config.radio.bw));
     setSf(String(config.radio.sf));
@@ -145,6 +147,7 @@ export function SettingsRadioSection({
     const parsedLat = parseFloat(lat);
     const parsedLon = parseFloat(lon);
     const parsedTxPower = parseInt(txPower, 10);
+    const parsedPathHashMode = parseInt(pathHashMode, 10);
     const parsedFreq = parseFloat(freq);
     const parsedBw = parseFloat(bw);
     const parsedSf = parseInt(sf, 10);
@@ -159,11 +162,20 @@ export function SettingsRadioSection({
       return null;
     }
 
+    if (
+      config.path_hash_mode_supported &&
+      (isNaN(parsedPathHashMode) || parsedPathHashMode < 0 || parsedPathHashMode > 2)
+    ) {
+      setError('Path hash mode must be between 0 and 2');
+      return null;
+    }
+
     return {
       name,
       lat: parsedLat,
       lon: parsedLon,
       tx_power: parsedTxPower,
+      ...(config.path_hash_mode_supported && { path_hash_mode: parsedPathHashMode }),
       radio: {
         freq: parsedFreq,
         bw: parsedBw,
@@ -384,6 +396,26 @@ export function SettingsRadioSection({
         </div>
       </div>
 
+      <div className="space-y-2">
+        <Label htmlFor="path-hash-mode">Path Hash Mode</Label>
+        <select
+          id="path-hash-mode"
+          value={pathHashMode}
+          onChange={(e) => setPathHashMode(e.target.value)}
+          disabled={!config.path_hash_mode_supported}
+          className="w-full h-10 px-3 rounded-md border border-input bg-background text-sm ring-offset-background focus:outline-none focus:ring-2 focus:ring-ring focus:ring-offset-2 disabled:cursor-not-allowed disabled:opacity-50"
+        >
+          <option value="0">1 byte per hop</option>
+          <option value="1">2 bytes per hop</option>
+          <option value="2">3 bytes per hop</option>
+        </select>
+        <p className="text-xs text-muted-foreground">
+          {config.path_hash_mode_supported
+            ? 'Controls the default hop hash width your radio uses for outbound routed paths.'
+            : 'Connected radio or firmware does not expose this setting.'}
+        </p>
+      </div>
+
       <Separator />
 
       <div className="space-y-2">

frontend/src/test/appFavorites.test.tsx

@@ -173,6 +173,8 @@ const baseConfig = {
   lon: 0,
   tx_power: 17,
   max_tx_power: 22,
+  path_hash_mode: 0,
+  path_hash_mode_supported: true,
   radio: { freq: 910.525, bw: 62.5, sf: 7, cr: 5 },
 };
 

frontend/src/test/appSearchJump.test.tsx

@@ -201,6 +201,8 @@ describe('App search jump target handling', () => {
       lon: 0,
       tx_power: 17,
       max_tx_power: 22,
+      path_hash_mode: 0,
+      path_hash_mode_supported: true,
       radio: { freq: 910.525, bw: 62.5, sf: 7, cr: 5 },
     });
     mocks.api.getSettings.mockResolvedValue({

frontend/src/test/appStartupHash.test.tsx

@@ -157,6 +157,8 @@ describe('App startup hash resolution', () => {
       lon: 0,
       tx_power: 17,
       max_tx_power: 22,
+      path_hash_mode: 0,
+      path_hash_mode_supported: true,
       radio: { freq: 910.525, bw: 62.5, sf: 7, cr: 5 },
     });
     mocks.api.getSettings.mockResolvedValue({

frontend/src/test/pathUtils.test.ts

@@ -40,6 +40,8 @@ function createConfig(overrides: Partial<RadioConfig> = {}): RadioConfig {
     lon: -74.006,
     tx_power: 10,
     max_tx_power: 20,
+    path_hash_mode: 0,
+    path_hash_mode_supported: true,
     radio: { freq: 915, bw: 250, sf: 10, cr: 8 },
     ...overrides,
   };

frontend/src/test/settingsModal.test.tsx

@@ -24,6 +24,8 @@ const baseConfig: RadioConfig = {
   lon: 2,
   tx_power: 17,
   max_tx_power: 22,
+  path_hash_mode: 1,
+  path_hash_mode_supported: true,
   radio: {
     freq: 910.525,
     bw: 62.5,
@@ -57,6 +59,7 @@ const baseSettings: AppSettings = {
 };
 
 function renderModal(overrides?: {
+  config?: RadioConfig;
   appSettings?: AppSettings;
   health?: HealthStatus;
   onSaveAppSettings?: (update: AppSettingsUpdate) => Promise<void>;
@@ -83,7 +86,7 @@ function renderModal(overrides?: {
   const commonProps = {
     open: overrides?.open ?? true,
     pageMode: overrides?.pageMode,
-    config: baseConfig,
+    config: overrides?.config ?? baseConfig,
     health: overrides?.health ?? baseHealth,
     appSettings: overrides?.appSettings ?? baseSettings,
     onClose,
@@ -218,6 +221,36 @@ describe('SettingsModal', () => {
     });
   });
 
+  it('saves radio path hash mode through onSave', async () => {
+    const { onSave } = renderModal();
+    openRadioSection();
+
+    fireEvent.change(screen.getByLabelText('Path Hash Mode'), {
+      target: { value: '2' },
+    });
+    fireEvent.click(screen.getByRole('button', { name: 'Save' }));
+
+    await waitFor(() => {
+      expect(onSave).toHaveBeenCalledWith(
+        expect.objectContaining({
+          path_hash_mode: 2,
+        })
+      );
+    });
+  });
+
+  it('disables path hash mode when the connected radio does not expose it', () => {
+    renderModal({
+      config: { ...baseConfig, path_hash_mode_supported: false },
+    });
+    openRadioSection();
+
+    expect(screen.getByLabelText('Path Hash Mode')).toBeDisabled();
+    expect(
+      screen.getByText('Connected radio or firmware does not expose this setting.')
+    ).toBeInTheDocument();
+  });
+
   it('renders selected section from external sidebar nav on desktop mode', async () => {
     renderModal({
       externalSidebarNav: true,

frontend/src/types.ts

@@ -12,6 +12,8 @@ export interface RadioConfig {
   lon: number;
   tx_power: number;
   max_tx_power: number;
+  path_hash_mode: number;
+  path_hash_mode_supported: boolean;
   radio: RadioSettings;
 }
 
@@ -20,6 +22,7 @@ export interface RadioConfigUpdate {
   lat?: number;
   lon?: number;
   tx_power?: number;
+  path_hash_mode?: number;
   radio?: RadioSettings;
 }