사내/사외 모드 회귀 보강: 전환 즉시반영 및 URL 경계 테스트 추가

- OperationModePolicyTests에 IsExternalUrl 경계 케이스(http/https vs file/mailto) 추가

- OperationModeReadinessTests 정비 및 internal→external 전환 즉시반영 테스트 추가

- README/DEVELOPMENT 이력(2026-04-04 16:24 KST) 동기화

src/AxCopilot.Tests/Services/OperationModePolicyTests.cs

@@ -31,6 +31,16 @@ public class OperationModePolicyTests
         OperationModePolicy.IsBlockedAgentToolInInternalMode("open_external", @"E:\work\report.html").Should().BeFalse();
     }
 
+    [Fact]
+    public void IsExternalUrl_DetectsOnlyHttpSchemes()
+    {
+        OperationModePolicy.IsExternalUrl("https://example.com").Should().BeTrue();
+        OperationModePolicy.IsExternalUrl("http://intranet.local").Should().BeTrue();
+        OperationModePolicy.IsExternalUrl(@"E:\work\report.html").Should().BeFalse();
+        OperationModePolicy.IsExternalUrl("mailto:admin@example.com").Should().BeFalse();
+        OperationModePolicy.IsExternalUrl("not-a-url").Should().BeFalse();
+    }
+
     [Fact]
     public async Task AgentContext_CheckToolPermissionAsync_BlocksRestrictedToolsInInternalMode()
     {

src/AxCopilot.Tests/Services/OperationModeReadinessTests.cs

@@ -0,0 +1,90 @@
+using System.Text.Json;
+using AxCopilot.Handlers;
+using AxCopilot.Services;
+using AxCopilot.Services.Agent;
+using FluentAssertions;
+using Xunit;
+
+namespace AxCopilot.Tests.Services;
+
+public class OperationModeReadinessTests
+{
+    [Fact]
+    public async Task WebSearch_InternalMode_ShowsBlockedMessage()
+    {
+        var settings = new SettingsService();
+        settings.Settings.OperationMode = OperationModePolicy.InternalMode;
+        var handler = new WebSearchHandler(settings);
+
+        var items = (await handler.GetItemsAsync("ax copilot", CancellationToken.None)).ToList();
+
+        items.Should().NotBeEmpty();
+        items[0].Title.Should().Contain("차단");
+    }
+
+    [Fact]
+    public async Task WebSearch_ExternalMode_ReturnsSearchItems()
+    {
+        var settings = new SettingsService();
+        settings.Settings.OperationMode = OperationModePolicy.ExternalMode;
+        var handler = new WebSearchHandler(settings);
+
+        var items = (await handler.GetItemsAsync("ax copilot", CancellationToken.None)).ToList();
+
+        items.Should().NotBeEmpty();
+        items.Any(i => i.Title.Contains("검색")).Should().BeTrue();
+        items.Any(i => i.Title.Contains("차단")).Should().BeFalse();
+    }
+
+    [Fact]
+    public async Task WebSearch_ModeSwitch_InternalToExternal_ShouldReflectImmediately()
+    {
+        var settings = new SettingsService();
+        var handler = new WebSearchHandler(settings);
+
+        settings.Settings.OperationMode = OperationModePolicy.InternalMode;
+        var internalItems = (await handler.GetItemsAsync("ax copilot", CancellationToken.None)).ToList();
+
+        settings.Settings.OperationMode = OperationModePolicy.ExternalMode;
+        var externalItems = (await handler.GetItemsAsync("ax copilot", CancellationToken.None)).ToList();
+
+        internalItems.Should().NotBeEmpty();
+        externalItems.Should().NotBeEmpty();
+        internalItems[0].Title.Should().Contain("차단");
+        externalItems.Any(i => i.Title.Contains("검색")).Should().BeTrue();
+    }
+
+    [Fact]
+    public async Task HttpTool_InternalMode_IsBlockedEvenWhenCalledDirectly()
+    {
+        var tool = new HttpTool();
+        using var doc = JsonDocument.Parse("""{"method":"GET","url":"http://127.0.0.1:8080/health"}""");
+        var context = new AgentContext
+        {
+            OperationMode = OperationModePolicy.InternalMode,
+            Permission = "Auto"
+        };
+
+        var result = await tool.ExecuteAsync(doc.RootElement, context, CancellationToken.None);
+
+        result.Success.Should().BeFalse();
+        result.Output.Should().Contain("사내모드");
+    }
+
+    [Fact]
+    public async Task OpenExternal_InternalMode_BlocksExternalUrl()
+    {
+        var tool = new OpenExternalTool();
+        using var doc = JsonDocument.Parse("""{"path":"https://example.com"}""");
+        var context = new AgentContext
+        {
+            OperationMode = OperationModePolicy.InternalMode,
+            Permission = "Auto"
+        };
+
+        var result = await tool.ExecuteAsync(doc.RootElement, context, CancellationToken.None);
+
+        result.Success.Should().BeFalse();
+        result.Output.Should().Contain("사내모드");
+    }
+}