fix: handle empty archetype roots and dot-root schema detection

Agent-Logs-Url: https://github.com/jeduden/mdsmith/sessions/31dd099c-4fd7-425e-b885-0ac1eec24901

Co-authored-by: jeduden <1117699+jeduden@users.noreply.github.com>

Author: Copilot

internal/archetypes/archetypes.go

@@ -40,10 +40,14 @@ type Resolver struct {
 // configured. It is applied when Resolver.Roots is empty.
 const DefaultRoot = "archetypes"
 
-// ValidateRoot returns an error when root is an absolute path or a
+// ValidateRoot returns an error when root is empty, absolute, or a
 // parent-traversal path. Archetype roots are expected to be
 // relative to the project root so they cannot reach outside it.
 func ValidateRoot(root string) error {
+	if strings.TrimSpace(root) == "" {
+		return fmt.Errorf(
+			"archetype root %q must not be empty", root)
+	}
 	if filepath.IsAbs(root) {
 		return fmt.Errorf(
 			"archetype root %q must be a relative path", root)

internal/archetypes/archetypes_test.go

@@ -252,8 +252,11 @@ func TestValidateRoot(t *testing.T) {
 		root    string
 		wantErr bool
 	}{
+		{"", true},
+		{"   ", true},
 		{"archetypes", false},
 		{"./archetypes", false},
+		{".", false},
 		{"internal/archetypes", false},
 		{"/abs", true},
 		{"..", true},

internal/rules/requiredstructure/rule.go

@@ -252,10 +252,16 @@ func (r *Rule) isSchemaOrArchetypeFile(f *lint.File) bool {
 		}
 	}
 	for _, root := range roots {
-		cleanRoot := filepath.ToSlash(filepath.Clean(root)) + "/"
+		cleanRoot := filepath.ToSlash(filepath.Clean(root))
+		if cleanRoot == "." {
+			cleanRoot = ""
+		} else {
+			cleanRoot += "/"
+		}
 		for _, c := range candidates {
-			if strings.HasPrefix(c, cleanRoot) &&
-				strings.HasSuffix(c, ".md") {
+			if strings.HasSuffix(c, ".md") &&
+				(cleanRoot == "" ||
+					strings.HasPrefix(c, cleanRoot)) {
 				return true
 			}
 		}

internal/rules/requiredstructure/rule_test.go

@@ -414,6 +414,17 @@ func TestCheck_ArchetypeRootFileSuppressesRequireWarning(t *testing.T) {
 	}
 }
 
+func TestCheck_DotArchetypeRootFileSuppressesRequireWarning(t *testing.T) {
+	root := t.TempDir()
+	f := newFileInRoot(t, root, "story.md",
+		"<?require\nfilename: \"story-*.md\"\n?>\n# ?\n")
+	r := &Rule{ArchetypeRoots: []string{"."}}
+	diags := r.Check(f)
+	for _, d := range diags {
+		assert.NotContains(t, d.Message, "<?require?>")
+	}
+}
+
 func TestCheck_ArchetypeEarlierRootShadowsLater(t *testing.T) {
 	root := t.TempDir()
 	writeArchetype(t, filepath.Join(root, "custom"), "story",

plan/52_archetype-template-library.md

@@ -42,8 +42,10 @@ against those roots.
    config file).
 5. Add `mdsmith archetypes list` to print each
    discovered archetype as `<name>\t<path>`, one per
-   line, sorted by name. Exit non-zero if no roots
-   are configured.
+   line, sorted by name. When `archetypes.roots` is
+   omitted, search the default `./archetypes`
+   directory. Exit non-zero if no archetypes are
+   discovered.
 6. Add `mdsmith archetypes show <name>` to print the
    archetype source (including front matter) to
    stdout. Exit non-zero with a clear error when the