fix: stabilize broker display models

apps/frontend/src/pages/broker/brokerAllocation.test.ts

@@ -95,6 +95,22 @@ describe('buildBrokerAllocation', () => {
     ]);
   });
 
+  it('ignores a tiny negative residual caused by decimal arithmetic', () => {
+    const result = buildBrokerAllocation(portfolio({ shares: 0.1, bonds: 0.2, portfolio: 0.3 }));
+
+    expect(result.sectors.map(({ key }) => key)).toEqual(['shares', 'bonds']);
+    expect(result.negative).toEqual([]);
+  });
+
+  it('ignores a tiny positive residual caused by decimal arithmetic', () => {
+    const result = buildBrokerAllocation(
+      portfolio({ shares: 0.3, portfolio: 0.30000000000000004 }),
+    );
+
+    expect(result.sectors.map(({ key }) => key)).toEqual(['shares']);
+    expect(result.negative).toEqual([]);
+  });
+
   it('returns no allocation for missing or nonpositive portfolio totals', () => {
     expect(buildBrokerAllocation(portfolio({ shares: 100, portfolio: null }))).toEqual({
       total: 0,

apps/frontend/src/pages/broker/brokerAllocation.ts

@@ -32,12 +32,22 @@ export function buildBrokerAllocation(portfolio: BrokerPortfolio): {
   const bonds = portfolio.totals.bonds?.value ?? 0;
   const etf = portfolio.totals.etf?.value ?? 0;
   const cash = portfolio.totals.currencies?.value ?? 0;
+  const mappedTotal = shares + bonds + etf + cash;
+  const residual = total - mappedTotal;
+  const residualTolerance =
+    Number.EPSILON *
+    Math.max(
+      1,
+      Math.abs(total),
+      Math.abs(shares) + Math.abs(bonds) + Math.abs(etf) + Math.abs(cash),
+    ) *
+    8;
   const values: Record<BrokerAllocationKey, number> = {
     shares,
     bonds,
     etf,
     cash,
-    other: total - shares - bonds - etf - cash,
+    other: Math.abs(residual) <= residualTolerance ? 0 : residual,
   };
 
   const sectors: BrokerAllocationItem[] = [];

apps/frontend/src/pages/broker/brokerDisplay.test.ts

@@ -138,6 +138,11 @@ describe('broker display helpers', () => {
     expect(labels).toEqual([...labels].sort((left, right) => left.localeCompare(right, 'ru')));
   });
 
+  it('keeps operation type options immutable at runtime', () => {
+    expect(Object.isFrozen(BROKER_OPERATION_TYPE_OPTIONS)).toBe(true);
+    expect(BROKER_OPERATION_TYPE_OPTIONS.every((option) => Object.isFrozen(option))).toBe(true);
+  });
+
   it('validates only exact known operation type values', () => {
     expect(isBrokerOperationType('OPERATION_TYPE_COUPON')).toBe(true);
     expect(isBrokerOperationType('operation_type_coupon')).toBe(false);

apps/frontend/src/pages/broker/brokerDisplay.ts

@@ -94,9 +94,13 @@ const OPERATION_TYPE_LABELS: Record<string, string> = {
   OPERATION_TYPE_OUTPUT_SECURITIES: 'Списание бумаг',
 };
 
-export const BROKER_OPERATION_TYPE_OPTIONS = Object.entries(OPERATION_TYPE_LABELS)
-  .map(([value, label]) => ({ value, label }))
-  .sort((left, right) => left.label.localeCompare(right.label, 'ru'));
+export const BROKER_OPERATION_TYPE_OPTIONS: ReadonlyArray<
+  Readonly<{ value: string; label: string }>
+> = Object.freeze(
+  Object.entries(OPERATION_TYPE_LABELS)
+    .map(([value, label]) => Object.freeze({ value, label }))
+    .sort((left, right) => left.label.localeCompare(right.label, 'ru')),
+);
 
 const BROKER_OPERATION_TYPES = new Set(BROKER_OPERATION_TYPE_OPTIONS.map(({ value }) => value));