fix(tests): make directory configuration tests environment-neutral

The directory configuration tests were hardcoded to expect dev container
paths like '/workspaces/flowtime-vnext/data' which caused CI failures
when running in GitHub Actions environment with different paths.

Changes:
- Updated CLI tests to use DirectoryProvider.GetDefaultDataDirectory()
- Updated API tests to use DirectoryProvider.GetDefaultDataDirectory()
- Updated Core tests to verify solution root discovery works correctly
- Added proper using statements for DirectoryProvider

Tests now dynamically discover the solution root and verify correct
data directory resolution regardless of environment (dev container,
CI, local development, etc.).

Author: 23min

tests/FlowTime.Api.Tests/ConfigurationTests.cs

@@ -1,3 +1,4 @@
+using FlowTime.Core.Configuration;
 using Microsoft.Extensions.Configuration;
 using Xunit;
 
@@ -67,7 +68,7 @@ public void GetArtifactsDirectory_NoConfiguration_ReturnsDefaultData()
     {
         // Arrange
         var configuration = new ConfigurationBuilder().Build();
-        var expectedPath = "/workspaces/flowtime-vnext/data";
+        var expectedPath = DirectoryProvider.GetDefaultDataDirectory();
 
         // Ensure no environment variable or configuration
         Environment.SetEnvironmentVariable("FLOWTIME_DATA_DIR", null);

tests/FlowTime.Cli.Tests/OutputDirectoryConfigurationTests.cs

@@ -1,4 +1,5 @@
 using FlowTime.Cli.Configuration;
+using FlowTime.Core.Configuration;
 using System;
 using System.IO;
 using Xunit;
@@ -50,7 +51,7 @@ public void GetDefaultOutputDirectory_NoEnvironmentVariable_ReturnsDefaultData()
     {
         // Arrange
         Environment.SetEnvironmentVariable("FLOWTIME_DATA_DIR", null);
-        var expectedPath = "/workspaces/flowtime-vnext/data";
+        var expectedPath = DirectoryProvider.GetDefaultDataDirectory();
 
         // Act
         var result = OutputDirectoryProvider.GetDefaultOutputDirectory();
@@ -64,7 +65,7 @@ public void GetDefaultOutputDirectory_EmptyEnvironmentVariable_FallsBackToDefaul
     {
         // Arrange
         Environment.SetEnvironmentVariable("FLOWTIME_DATA_DIR", string.Empty);
-        var expectedPath = "/workspaces/flowtime-vnext/data";
+        var expectedPath = DirectoryProvider.GetDefaultDataDirectory();
 
         // Act
         var result = OutputDirectoryProvider.GetDefaultOutputDirectory();
@@ -78,7 +79,7 @@ public void GetDefaultOutputDirectory_WhitespaceEnvironmentVariable_FallsBackToD
     {
         // Arrange
         Environment.SetEnvironmentVariable("FLOWTIME_DATA_DIR", "   ");
-        var expectedPath = "/workspaces/flowtime-vnext/data";
+        var expectedPath = DirectoryProvider.GetDefaultDataDirectory();
 
         // Act
         var result = OutputDirectoryProvider.GetDefaultOutputDirectory();

tests/FlowTime.Tests/Configuration/DirectoryProviderTests.cs

@@ -12,11 +12,15 @@ public void GetDefaultDataDirectory_FindsSolutionRoot()
 
         // Assert
         // Should find the solution root and append /data
-        Assert.Contains("flowtime-vnext", dataDir);
         Assert.EndsWith("data", dataDir);
 
         // Should not be relative to current directory when solution root is found
         Assert.DoesNotContain("FlowTime.Tests", dataDir);
+        
+        // Should contain the directory where FlowTime.sln exists
+        var solutionRoot = DirectoryProvider.FindSolutionRoot();
+        Assert.NotNull(solutionRoot);
+        Assert.Equal(Path.Combine(solutionRoot, "data"), dataDir);
     }
 
     [Fact]