fix(web): tolerate null drive-ledger dynamics on drive detail

web/src/api/types.ts

@@ -3793,17 +3793,19 @@ export interface PhysicsLedger {
   kind: string
   start: string
   end: string
-  dynamics: PhysicsLongitudinalDynamics
-  drive: PhysicsDriveLedger
-  charge: PhysicsChargeLedger
-  park: PhysicsParkLedger
-  thermal: PhysicsThermalLedger
-  range: PhysicsRangeLedger
-  tires: PhysicsTireLedger
-  epochs: PhysicsEpochResidual[]
-  unknown_intervals: PhysicsUnknownInterval[]
+  // Nested ledgers are Go pointers; encoding/json emits null (or omits
+  // after camelCase transforms) when that domain has no samples.
+  dynamics: PhysicsLongitudinalDynamics | null
+  drive: PhysicsDriveLedger | null
+  charge: PhysicsChargeLedger | null
+  park: PhysicsParkLedger | null
+  thermal: PhysicsThermalLedger | null
+  range: PhysicsRangeLedger | null
+  tires: PhysicsTireLedger | null
+  epochs: PhysicsEpochResidual[] | null
+  unknown_intervals: PhysicsUnknownInterval[] | null
   unknown_hours: number
-  black_box: PhysicsBlackBoxPoint[]
+  black_box: PhysicsBlackBoxPoint[] | null
   contradictions?: string[]
   markers?: PhysicsMarker[]
   truncated: boolean

web/src/features/driving/components/drive-detail/DriveLedgerCompactPanel.test.tsx

@@ -0,0 +1,121 @@
+/**
+ * DriveLedgerCompactPanel — Go nil nested ledgers must not crash.
+ *
+ * encoding/json marshals a nil *LongitudinalDynamics as JSON null. After
+ * camelCaseKeys the field can also be missing (undefined). Accessing
+ * `.regen_wh` on that value used to throw and trip the drive-detail
+ * energy-ledger error boundary.
+ */
+
+import { describe, it, expect, beforeEach, vi } from 'vitest';
+import { render, screen } from '@testing-library/react';
+import { MemoryRouter } from 'react-router-dom';
+import type { PhysicsLedger } from '@/api/types';
+
+vi.mock('react-i18next', () => ({
+  useTranslation: () => ({
+    t: (_key: string, fallback?: string) => fallback ?? _key,
+    i18n: { language: 'en', changeLanguage: vi.fn() },
+  }),
+}));
+
+const { useDriveLedgerMock } = vi.hoisted(() => ({
+  useDriveLedgerMock: vi.fn(),
+}));
+
+vi.mock('@/api/hooks/usePhysicsLedger', () => ({
+  useDriveLedger: useDriveLedgerMock,
+}));
+
+import { DriveLedgerCompactPanel } from './DriveLedgerCompactPanel';
+
+function queryState(over: Record<string, unknown> = {}) {
+  return {
+    data: undefined,
+    dataUpdatedAt: Date.now(),
+    error: null,
+    isError: false,
+    isPending: false,
+    isLoading: false,
+    isFetching: false,
+    isSuccess: true,
+    status: 'success',
+    fetchStatus: 'idle',
+    refetch: vi.fn(),
+    ...over,
+  };
+}
+
+function ledgerStub(over: Partial<PhysicsLedger> = {}): PhysicsLedger {
+  return {
+    vehicle_id: 1,
+    kind: 'drive',
+    start: '2026-09-17T12:00:00Z',
+    end: '2026-09-17T13:00:00Z',
+    dynamics: null,
+    drive: null,
+    charge: null,
+    park: null,
+    thermal: null,
+    range: null,
+    tires: null,
+    epochs: null,
+    unknown_intervals: null,
+    unknown_hours: 0,
+    black_box: null,
+    truncated: false,
+    honesty: 'Predicted vs measured.',
+    ...over,
+  };
+}
+
+function renderPanel() {
+  return render(
+    <MemoryRouter>
+      <DriveLedgerCompactPanel driveId="393" />
+    </MemoryRouter>,
+  );
+}
+
+describe('DriveLedgerCompactPanel', () => {
+  beforeEach(() => {
+    useDriveLedgerMock.mockReset();
+  });
+
+  it('renders regen/friction as Unknown when dynamics is JSON null', () => {
+    useDriveLedgerMock.mockReturnValue(queryState({ data: ledgerStub({ dynamics: null }) }));
+    expect(() => renderPanel()).not.toThrow();
+    expect(screen.getByTestId('drive-ledger-compact')).toBeInTheDocument();
+    expect(screen.getByText(/Regen/)).toHaveTextContent(/Unknown/);
+    expect(screen.getByText(/Friction brake/)).toHaveTextContent(/Unknown/);
+  });
+
+  it('does not crash when dynamics is omitted (undefined)', () => {
+    const data = ledgerStub();
+    delete (data as { dynamics?: PhysicsLedger['dynamics'] }).dynamics;
+    useDriveLedgerMock.mockReturnValue(queryState({ data }));
+    expect(() => renderPanel()).not.toThrow();
+    expect(screen.getByTestId('drive-ledger-compact')).toBeInTheDocument();
+    expect(screen.getByText(/Regen/)).toHaveTextContent(/Unknown/);
+  });
+
+  it('shows formatted regen when dynamics is present', () => {
+    useDriveLedgerMock.mockReturnValue(
+      queryState({
+        data: ledgerStub({
+          dynamics: {
+            points: [],
+            mass_kg: null,
+            mass_source: 'unknown',
+            regen_wh: 4880,
+            friction_brake_wh: 0,
+            unknown: false,
+            honesty: 'Regen is pack charge current while moving.',
+          },
+        }),
+      }),
+    );
+    renderPanel();
+    expect(screen.getByText(/Regen/)).not.toHaveTextContent(/Unknown/);
+  });
+});

web/src/features/driving/components/drive-detail/DriveLedgerCompactPanel.tsx

@@ -32,11 +32,15 @@ export function DriveLedgerCompactPanel({ driveId }: { driveId: string | undefin
           <div className="flex flex-wrap gap-2">
             <Badge variant="neutral" size="sm">
               {t('driveDetail.ledger.regen', 'Regen')}:{' '}
-              {ledger.dynamics.regen_wh != null ? formatEnergy(ledger.dynamics.regen_wh) : t('common.unknown', 'Unknown')}
+              {ledger.dynamics?.regen_wh != null
+                ? formatEnergy(ledger.dynamics.regen_wh)
+                : t('common.unknown', 'Unknown')}
             </Badge>
             <Badge variant="neutral" size="sm">
               {t('driveDetail.ledger.friction', 'Friction brake')}:{' '}
-              {ledger.dynamics.friction_brake_wh != null ? formatEnergy(ledger.dynamics.friction_brake_wh) : t('common.unknown', 'Unknown')}
+              {ledger.dynamics?.friction_brake_wh != null
+                ? formatEnergy(ledger.dynamics.friction_brake_wh)
+                : t('common.unknown', 'Unknown')}
             </Badge>
             {ledger.truncated ? (
               <Badge variant="danger" size="sm">