DC-241: Fix CO household ID type and support arrays in AppConfig (#121)

* DC-241: Set CO household ID type to Phone via environment variable

CO was falling back to the base appsettings.json default of Email
because AppConfig does not support array values. This adds the
StateHouseholdId__PreferredHouseholdIdTypes__0 env var to the CO
ECS task definition so households are resolved by phone as intended.

* DC-241: Support JSON arrays in AppConfig configuration provider

The AppConfig freeform provider previously skipped arrays with a
warning, making it impossible to override array-based settings like
StateHouseholdId:PreferredHouseholdIdTypes via AppConfig. Arrays are
now flattened using indexed keys (e.g. Key:0, Key:1) matching the
ASP.NET Core JSON configuration convention.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: James Blair <jblair@codeforamerica.org>
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: 3 people

src/SEBT.Portal.Infrastructure/Configuration/AppConfigAgentConfigurationProvider.cs

@@ -231,8 +231,12 @@ private void FlattenJsonElement(JsonElement element, Dictionary<string, string?>
                 FlattenJsonObject(element, result, key);
                 break;
             case JsonValueKind.Array:
-                // Arrays are not supported in configuration
-                _logger?.LogWarning("JSON arrays are not supported in configuration. Skipping key: {Key}", key);
+                var index = 0;
+                foreach (var item in element.EnumerateArray())
+                {
+                    FlattenJsonElement(item, result, $"{key}:{index}");
+                    index++;
+                }
                 break;
             case JsonValueKind.String:
                 result[key] = element.GetString();

test/SEBT.Portal.Tests/Unit/Configuration/AppConfigAgentConfigurationProviderTests.cs

@@ -321,7 +321,7 @@ public void Load_WithNullValues_ShouldHandleCorrectly()
     }
 
     [Fact]
-    public void Load_WithArrays_ShouldSkipArrays()
+    public void Load_WithStringArray_ShouldFlattenWithIndexedKeys()
     {
         // Arrange
         var profile = new AppConfigAgentProfile
@@ -336,7 +336,7 @@ public void Load_WithArrays_ShouldSkipArrays()
         var configJson = new
         {
             Key1 = "value1",
-            ArrayKey = new[] { "item1", "item2" }
+            ArrayKey = new[] { "item1", "item2", "item3" }
         };
 
         _mockHttpHandler
@@ -351,8 +351,158 @@ public void Load_WithArrays_ShouldSkipArrays()
         // Assert
         Assert.True(provider.TryGet("Key1", out var key1));
         Assert.Equal("value1", key1);
-        // arrays should be skipped
-        Assert.False(provider.TryGet("ArrayKey", out _));
+        Assert.True(provider.TryGet("ArrayKey:0", out var item0));
+        Assert.Equal("item1", item0);
+        Assert.True(provider.TryGet("ArrayKey:1", out var item1));
+        Assert.Equal("item2", item1);
+        Assert.True(provider.TryGet("ArrayKey:2", out var item2));
+        Assert.Equal("item3", item2);
+    }
+
+    [Fact]
+    public void Load_WithNestedConfigArray_ShouldFlattenWithSectionAndIndex()
+    {
+        // Arrange — mirrors the real StateHouseholdId config structure
+        var profile = new AppConfigAgentProfile
+        {
+            BaseUrl = "http://localhost:2772",
+            ApplicationId = "test-app",
+            EnvironmentId = "test-env",
+            ProfileId = "test-profile",
+            IsFeatureFlag = false
+        };
+
+        var configJson = new
+        {
+            StateHouseholdId = new
+            {
+                PreferredHouseholdIdTypes = new[] { "Phone" }
+            }
+        };
+
+        _mockHttpHandler
+            .When("http://localhost:2772/applications/test-app/environments/test-env/configurations/test-profile")
+            .Respond(HttpStatusCode.OK, "application/json", JsonSerializer.Serialize(configJson));
+
+        var provider = new AppConfigAgentConfigurationProvider(_httpClient, profile, _logger, ownsHttpClient: false);
+
+        // Act
+        provider.Load();
+
+        // Assert
+        Assert.True(provider.TryGet("StateHouseholdId:PreferredHouseholdIdTypes:0", out var type0));
+        Assert.Equal("Phone", type0);
+    }
+
+    [Fact]
+    public void Load_WithArrayOfObjects_ShouldFlattenWithIndexAndPropertyKeys()
+    {
+        // Arrange
+        var profile = new AppConfigAgentProfile
+        {
+            BaseUrl = "http://localhost:2772",
+            ApplicationId = "test-app",
+            EnvironmentId = "test-env",
+            ProfileId = "test-profile",
+            IsFeatureFlag = false
+        };
+
+        var configJson = new
+        {
+            Items = new[]
+            {
+                new { Name = "first", Value = 1 },
+                new { Name = "second", Value = 2 }
+            }
+        };
+
+        _mockHttpHandler
+            .When("http://localhost:2772/applications/test-app/environments/test-env/configurations/test-profile")
+            .Respond(HttpStatusCode.OK, "application/json", JsonSerializer.Serialize(configJson));
+
+        var provider = new AppConfigAgentConfigurationProvider(_httpClient, profile, _logger, ownsHttpClient: false);
+
+        // Act
+        provider.Load();
+
+        // Assert
+        Assert.True(provider.TryGet("Items:0:Name", out var name0));
+        Assert.Equal("first", name0);
+        Assert.True(provider.TryGet("Items:0:Value", out var value0));
+        Assert.Equal("1", value0);
+        Assert.True(provider.TryGet("Items:1:Name", out var name1));
+        Assert.Equal("second", name1);
+        Assert.True(provider.TryGet("Items:1:Value", out var value1));
+        Assert.Equal("2", value1);
+    }
+
+    [Fact]
+    public void Load_WithEmptyArray_ShouldProduceNoKeys()
+    {
+        // Arrange
+        var profile = new AppConfigAgentProfile
+        {
+            BaseUrl = "http://localhost:2772",
+            ApplicationId = "test-app",
+            EnvironmentId = "test-env",
+            ProfileId = "test-profile",
+            IsFeatureFlag = false
+        };
+
+        // Use raw JSON since anonymous types can't express empty typed arrays cleanly
+        var configJson = """{"Key1": "value1", "EmptyArray": []}""";
+
+        _mockHttpHandler
+            .When("http://localhost:2772/applications/test-app/environments/test-env/configurations/test-profile")
+            .Respond(HttpStatusCode.OK, "application/json", configJson);
+
+        var provider = new AppConfigAgentConfigurationProvider(_httpClient, profile, _logger, ownsHttpClient: false);
+
+        // Act
+        provider.Load();
+
+        // Assert
+        Assert.True(provider.TryGet("Key1", out var key1));
+        Assert.Equal("value1", key1);
+        Assert.False(provider.TryGet("EmptyArray:0", out _));
+    }
+
+    [Fact]
+    public void Load_WithMixedTypeArray_ShouldFlattenAllElementTypes()
+    {
+        // Arrange
+        var profile = new AppConfigAgentProfile
+        {
+            BaseUrl = "http://localhost:2772",
+            ApplicationId = "test-app",
+            EnvironmentId = "test-env",
+            ProfileId = "test-profile",
+            IsFeatureFlag = false
+        };
+
+        // Mixed types require raw JSON
+        var configJson = """{"Mixed": ["text", 42, true, false, null]}""";
+
+        _mockHttpHandler
+            .When("http://localhost:2772/applications/test-app/environments/test-env/configurations/test-profile")
+            .Respond(HttpStatusCode.OK, "application/json", configJson);
+
+        var provider = new AppConfigAgentConfigurationProvider(_httpClient, profile, _logger, ownsHttpClient: false);
+
+        // Act
+        provider.Load();
+
+        // Assert
+        Assert.True(provider.TryGet("Mixed:0", out var v0));
+        Assert.Equal("text", v0);
+        Assert.True(provider.TryGet("Mixed:1", out var v1));
+        Assert.Equal("42", v1);
+        Assert.True(provider.TryGet("Mixed:2", out var v2));
+        Assert.Equal("true", v2);
+        Assert.True(provider.TryGet("Mixed:3", out var v3));
+        Assert.Equal("false", v3);
+        Assert.True(provider.TryGet("Mixed:4", out var v4));
+        Assert.Null(v4);
     }
 
     [Fact]

tofu/config/dev-co/main.tf

@@ -109,9 +109,10 @@ module "app" {
   enable_appconfig       = true
 
   state_api_environment_variables = {
-    "Oidc__DiscoveryEndpoint"               = var.oidc_discovery_endpoint
-    "Oidc__CallbackRedirectUri"             = "https://${var.domain}/callback"
-    "Oidc__LanguageParam"                   = "en"
+    "Oidc__DiscoveryEndpoint"                          = var.oidc_discovery_endpoint
+    "Oidc__CallbackRedirectUri"                        = "https://${var.domain}/callback"
+    "Oidc__LanguageParam"                              = "en"
+    "StateHouseholdId__PreferredHouseholdIdTypes__0"   = "Phone"
   }
 
   state_api_environment_secrets = {