Report: show the solution path relative to where report runs

specs/codemap-indexer.md

@@ -360,8 +360,10 @@ reverse **blast radius** — how many scenarios reach it, via `EndpointReachAll`
 an **expandable toggle**: opening a row reveals the reached scenarios grouped by feature, each with the
 step text that connects it (via `EndpointScenarioDetails`, resolved only for the shown rows) — the same
 drill-down `impact --endpoint` prints, capped per row with a pointer to the CLI for the exhaustive list.
-All map-derived text is HTML-escaped. Deterministic: the only volatile value
-(the generated timestamp) is read from the map, not the clock. When the map's `user_version`
+All map-derived text is HTML-escaped. The header shows the solution path relative to the
+directory `report` runs from when the solution lies under it (forward slashes), so a committed
+report carries no machine-specific absolute path; otherwise it shows the path as recorded in the map.
+Deterministic: the only volatile value (the generated timestamp) is read from the map, not the clock. When the map's `user_version`
 predates the current schema, the report shows a **stale-schema banner** (and `report`/`search`
 print a matching console note) explaining that facets like Gherkin features / coverage / search are
 empty because the map is old — re-run `index` to populate them — so empty sections never read as a bug.

src/CodeMap.Cli/Program.cs

@@ -254,7 +254,7 @@ public static int RunReport(string[] args)
         string html;
         try
         {
-            html = HtmlReportBuilder.Build(doc);
+            html = HtmlReportBuilder.Build(doc, Environment.CurrentDirectory);
             File.WriteAllText(output, html);
         }
         catch (Exception ex)

src/CodeMap.Core/Reporting/HtmlReportBuilder.cs

@@ -16,7 +16,13 @@ namespace TestAtlas.Core.Reporting;
 public static class HtmlReportBuilder
 {
     /// <summary>Builds the full HTML document as a string.</summary>
-    public static string Build(MapDocument doc)
+    /// <param name="doc">The map to render.</param>
+    /// <param name="baseDirectory">
+    /// When given, a solution path under this directory is shown relative to it (forward slashes), so a
+    /// committed report doesn't carry the machine-specific absolute path. A solution outside it, or no
+    /// base directory, shows the path as recorded in the map.
+    /// </param>
+    public static string Build(MapDocument doc, string? baseDirectory = null)
     {
         var sb = new StringBuilder(64 * 1024);
 
@@ -42,7 +48,7 @@ public static string Build(MapDocument doc)
         var coveragePct = totalSteps == 0 ? 0 : (int)Math.Round(100.0 * resolved / totalSteps);
 
         // ---- document shell -----------------------------------------------------------------
-        var solutionPath = Meta(doc, MapSchema.MetaSolutionPath, "(unknown solution)");
+        var solutionPath = DisplayPath(Meta(doc, MapSchema.MetaSolutionPath, "(unknown solution)"), baseDirectory);
         var solutionName = Path.GetFileName(solutionPath);
         var generated = Meta(doc, MapSchema.MetaGeneratedUtc, "");
         var toolVersion = Meta(doc, MapSchema.MetaToolVersion, "");
@@ -616,6 +622,17 @@ private static void LegendItem(StringBuilder sb, string cls, int count, string d
              .Append("</b> <span class=\"lk\">").Append(cls).Append("</span> <span class=\"ld\">")
              .Append(E(desc)).Append("</span></li>");
 
+    /// <summary>The path relative to <paramref name="baseDirectory"/> when it lies under it; otherwise unchanged.</summary>
+    internal static string DisplayPath(string path, string? baseDirectory)
+    {
+        if (string.IsNullOrEmpty(baseDirectory) || !Path.IsPathFullyQualified(path)) return path;
+        var relative = Path.GetRelativePath(baseDirectory, path);
+        var outside = relative == ".." || relative.StartsWith("../", StringComparison.Ordinal)
+            || relative.StartsWith("..\\", StringComparison.Ordinal);
+        if (relative == "." || outside || Path.IsPathRooted(relative)) return path;
+        return relative.Replace('\\', '/');
+    }
+
     private static string Meta(MapDocument doc, string key, string fallback)
         => doc.Meta.TryGetValue(key, out var v) && v.Length > 0 ? v : fallback;
 

tests/CodeMap.Tests/HtmlReportBuilderTests.cs

@@ -56,6 +56,27 @@ public void Emits_a_self_contained_document()
         Assert.DoesNotContain("src=\"http", html);   // no external script/img
     }
 
+    [Fact]
+    public void Shows_the_solution_path_relative_to_the_base_directory()
+    {
+        var html = HtmlReportBuilder.Build(Doc(), "/repo");
+        Assert.Contains("<span title=\"My.sln\">My.sln</span>", html);
+        Assert.DoesNotContain("/repo/My.sln", html);
+
+        // No base directory: the path as recorded in the map, as before.
+        Assert.Contains("<span title=\"/repo/My.sln\">/repo/My.sln</span>", HtmlReportBuilder.Build(Doc()));
+    }
+
+    [Theory]
+    [InlineData("/repo/samples/Shop/Shop.sln", "/repo", "samples/Shop/Shop.sln")]
+    [InlineData("/repo/samples/Shop/Shop.sln", "/repo/", "samples/Shop/Shop.sln")]
+    [InlineData("/elsewhere/Shop.sln", "/repo", "/elsewhere/Shop.sln")]   // outside the base: unchanged
+    [InlineData("/repo/..x/Shop.sln", "/repo", "..x/Shop.sln")]          // a folder named "..x" is still inside
+    [InlineData("(unknown solution)", "/repo", "(unknown solution)")]    // not a path: unchanged
+    [InlineData("/repo/Shop.sln", null, "/repo/Shop.sln")]
+    public void Display_path_is_relative_only_under_the_base(string path, string? baseDirectory, string expected)
+        => Assert.Equal(expected, HtmlReportBuilder.DisplayPath(path, baseDirectory));
+
     [Fact]
     public void Renders_each_binding_state_with_its_evidence()
     {