feat: improve URL generation with added variations and simplified path handling

- Added trailing-slash variations for directory-style URLs in `OutputGenerationService`.
- Simplified relative path generation in `RecipeContentService` to improve output file path handling.

Author: phil-scott-78

examples/RecipeExample/RecipeContentService.cs

@@ -141,10 +141,8 @@ async Task<ImmutableList<PageToGenerate>> IContentService.GetPagesToGenerateAsyn
         // Add individual recipe pages
         foreach (var (url, recipePage) in data)
         {
-
-            var relativePath = url.Replace('/', Path.DirectorySeparatorChar);
-
-            var outputFile = _fileSystem.Path.Combine(_options.BasePageUrl, relativePath.Trim(Path.DirectorySeparatorChar), "index.html").TrimStart(Path.DirectorySeparatorChar);
+            var relativePath = url.TrimStart('/').Replace('/', Path.DirectorySeparatorChar);
+            var outputFile = _fileSystem.Path.Combine(relativePath, "index.html");
 
             pages.Add(new PageToGenerate(url, outputFile, new Metadata()
             {

src/MyLittleContentEngine/Services/Generation/OutputGenerationService.cs

@@ -557,6 +557,12 @@ private ImmutableHashSet<string> BuildValidOutputPathsLookup(
                 validPaths.Add(normalizedUrl + ".html");
             }
 
+            // Add trailing-slash variation for directory-style URLs
+            if (!normalizedUrl.EndsWith('/') && !Path.HasExtension(normalizedUrl))
+            {
+                validPaths.Add(normalizedUrl + "/");
+            }
+
             // Add version without .html extension for pages that have it
             // This allows both /about.html and /about to be valid
             if (normalizedUrl.EndsWith(".html", StringComparison.OrdinalIgnoreCase))