Fix Android doc test path resolution

On Android, Documentation.docc is copied flat to the working directory
without the Sources/SyntaxKit/ prefix. Centralize the prefix logic in
resolveFilePath so test methods use short paths and Settings adds the
prefix for non-Android platforms.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: leogdion

Tests/SyntaxDocTests/DocumentationExampleTests.swift

@@ -42,7 +42,7 @@ internal struct DocumentationExampleTests {
   @Test("Quick Start Guide examples work correctly")
   internal func validateQuickStartGuideExamples() throws {
     let quickStartFile = try Settings.resolveFilePath(
-      "Sources/SyntaxKit/Documentation.docc/Tutorials/Quick-Start-Guide.md"
+      "Documentation.docc/Tutorials/Quick-Start-Guide.md"
     )
     let results = try testHarness.validateFile(at: quickStartFile)
 
@@ -57,7 +57,7 @@ internal struct DocumentationExampleTests {
   @Test("Creating Macros tutorial examples work correctly")
   internal func validateMacroTutorialExamples() throws {
     let macroTutorialFile = try Settings.resolveFilePath(
-      "Sources/SyntaxKit/Documentation.docc/Tutorials/Creating-Macros-with-SyntaxKit.md"
+      "Documentation.docc/Tutorials/Creating-Macros-with-SyntaxKit.md"
     )
     let results = try testHarness.validateFile(at: macroTutorialFile)
 

Tests/SyntaxDocTests/Settings.swift

@@ -81,7 +81,12 @@ internal enum Settings {
         return .init(fileURLWithPath: filePath)
       }
     } else {
-      return Self.projectRoot.appendingPathComponent(filePath)
+      #if os(Android)
+      let resolvedPath = filePath
+      #else
+      let resolvedPath = "Sources/SyntaxKit/" + filePath
+      #endif
+      return Self.projectRoot.appendingPathComponent(resolvedPath)
     }
   }
 }