refactor(tests): adapt unified-session tests to no-circuit-breaker world

- Remove circuitBreakerTrips from the prometheus-metrics mock (metric
  no longer emitted now that telemetry path skips the circuit breaker).
- Drop the enableCircuitBreaker option from the default test setup.
- Replace the "with CircuitBreaker" describe block with an equivalent
  suite that asserts the same observable behavior (single send per call,
  failures swallowed gracefully) without requiring the option.

All 31 unified-session tests pass.

src/__tests__/Utils/unified-session.test.ts

@@ -29,8 +29,7 @@ const TimeMs = {
 jest.mock('../../Utils/prometheus-metrics.js', () => ({
 	metrics: {
 		socketEvents: { inc: jest.fn() },
-		errors: { inc: jest.fn() },
-		circuitBreakerTrips: { inc: jest.fn() }
+		errors: { inc: jest.fn() }
 	}
 }))
 
@@ -59,7 +58,6 @@ describe('UnifiedSessionManager', () => {
 		manager = createUnifiedSessionManager({
 			enabled: true,
 			logger: mockLogger as any,
-			enableCircuitBreaker: false, // Disable for simpler testing
 			sendNode: mockSendNode
 		})
 	})
@@ -356,7 +354,11 @@ describe('shouldEnableUnifiedSession', () => {
 	})
 })
 
-describe('UnifiedSessionManager with CircuitBreaker', () => {
+describe('UnifiedSessionManager — non-critical send semantics', () => {
+	// The previous "with CircuitBreaker" suite is gone — telemetry no longer
+	// uses a circuit breaker. Verify equivalent behavior still holds:
+	// failures are swallowed (telemetry is non-critical) and don't propagate.
+
 	let manager: UnifiedSessionManager
 	let mockSendNode: MockSendNode
 
@@ -366,7 +368,6 @@ describe('UnifiedSessionManager with CircuitBreaker', () => {
 		manager = createUnifiedSessionManager({
 			enabled: true,
 			logger: createMockLogger() as any,
-			enableCircuitBreaker: true,
 			sendNode: mockSendNode
 		})
 	})
@@ -375,24 +376,13 @@ describe('UnifiedSessionManager with CircuitBreaker', () => {
 		manager.destroy()
 	})
 
-	it('should work with circuit breaker enabled', async () => {
+	it('should send telemetry once per call', async () => {
 		await manager.send('login')
 		expect(mockSendNode).toHaveBeenCalledTimes(1)
 	})
 
-	it('should handle circuit breaker failures gracefully', async () => {
-		// Make send fail multiple times to trigger circuit breaker
-		let callCount = 0
-		mockSendNode.mockImplementation(async () => {
-			callCount++
-			if (callCount <= 3) {
-				throw new Error(`Fail ${callCount}`)
-			}
-		})
-
-		// These should not throw even with failures
-		await expect(manager.send('login')).resolves.toBeUndefined()
-		await expect(manager.send('login')).resolves.toBeUndefined()
+	it('should swallow send failures gracefully (telemetry is non-critical)', async () => {
+		mockSendNode.mockRejectedValueOnce(new Error('boom'))
 		await expect(manager.send('login')).resolves.toBeUndefined()
 	})
 })