fix: handle HTTPClient::KeepAliveDisconnected in OrgRegistrantPhoneCheckerJob

This commit implements a reliable connection error handling solution for the
Company Register API integration. The job previously failed when connection
errors occurred without proper recovery mechanisms.
The implementation:
Adds a lightweight Retryable module with configurable retry logic
Implements smart caching of API responses (1 day expiration)
Handles common network errors like KeepAliveDisconnected and timeouts
Provides a fallback mechanism when all retry attempts fail
Ensures test reliability with cache-skipping in test environment
Testing:
Added specific tests for both recovery and fallback scenarios
Verified cache behavior in production and test environments
Resolves connection errors observed in production logs without adding
unnecessary complexity to the codebase.

test/lib/retryable_test.rb

@@ -0,0 +1,68 @@
+# frozen_string_literal: true
+
+require 'test_helper'
+
+class RetryableTest < ActiveSupport::TestCase
+  class TestClass
+    include Retryable
+
+    attr_reader :call_count
+
+    def initialize
+      @call_count = 0
+    end
+
+    def test_retriable_method(should_fail: false, fail_count: 2)
+      with_retry(
+        max_attempts: 3,
+        retry_delay: 0.1,
+        logger: Rails.logger
+      ) do
+        @call_count += 1
+        
+        if should_fail && @call_count <= fail_count
+          raise StandardError, "Тестовая ошибка #{@call_count}"
+        end
+        
+        'success'
+      end
+    end
+
+    def test_retriable_with_fallback(should_fail: true)
+      with_retry(
+        max_attempts: 2,
+        retry_delay: 0.1,
+        logger: Rails.logger,
+        fallback: -> { 'fallback' }
+      ) do
+        @call_count += 1
+        raise StandardError, 'Постоянная ошибка' if should_fail
+        'success'
+      end
+    end
+  end
+
+  test 'should retry specified number of times and succeed' do
+    test_object = TestClass.new
+    result = test_object.test_retriable_method(should_fail: true, fail_count: 2)
+    
+    assert_equal 3, test_object.call_count
+    assert_equal 'success', result
+  end
+
+  test 'should succeed on first try if no errors' do
+    test_object = TestClass.new
+    result = test_object.test_retriable_method(should_fail: false)
+    
+    assert_equal 1, test_object.call_count
+    assert_equal 'success', result
+  end
+
+  test 'should use fallback when all retries fail' do
+    test_object = TestClass.new
+    result = test_object.test_retriable_with_fallback(should_fail: true)
+    
+    assert_equal 2, test_object.call_count
+    assert_equal 'fallback', result
+  end
+end