feat(help): add LoadContentDir for directory-based catalog loading

Co-Authored-By: Virgil <virgil@lethean.io>

pkg/help/catalog.go

@@ -2,9 +2,13 @@ package help
 
 import (
 	"fmt"
+	"io/fs"
 	"iter"
 	"maps"
+	"os"
+	"path/filepath"
 	"slices"
+	"strings"
 )
 
 // Catalog manages help topics.
@@ -90,6 +94,44 @@ func (c *Catalog) SearchResults(query string) iter.Seq[*SearchResult] {
 	return slices.Values(c.Search(query))
 }
 
+// LoadContentDir recursively loads all .md files from a directory into a Catalog.
+func LoadContentDir(dir string) (*Catalog, error) {
+	c := &Catalog{
+		topics: make(map[string]*Topic),
+		index:  newSearchIndex(),
+	}
+
+	err := filepath.WalkDir(dir, func(path string, d fs.DirEntry, err error) error {
+		if err != nil {
+			return err
+		}
+		if d.IsDir() {
+			return nil
+		}
+		if !strings.HasSuffix(strings.ToLower(d.Name()), ".md") {
+			return nil
+		}
+
+		content, err := os.ReadFile(path)
+		if err != nil {
+			return fmt.Errorf("reading %s: %w", path, err)
+		}
+
+		topic, err := ParseTopic(path, content)
+		if err != nil {
+			return fmt.Errorf("parsing %s: %w", path, err)
+		}
+
+		c.Add(topic)
+		return nil
+	})
+	if err != nil {
+		return nil, fmt.Errorf("walking directory %s: %w", dir, err)
+	}
+
+	return c, nil
+}
+
 // Get returns a topic by ID.
 func (c *Catalog) Get(id string) (*Topic, error) {
 	t, ok := c.topics[id]

pkg/help/catalog_test.go

@@ -2,6 +2,8 @@ package help
 
 import (
 	"fmt"
+	"os"
+	"path/filepath"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -176,6 +178,42 @@ func TestCatalog_Search_Good_ScoreTiebreaking(t *testing.T) {
 		"scores should be equal for tie-breaking to apply")
 }
 
+func TestCatalog_LoadContentDir_Good(t *testing.T) {
+	dir := t.TempDir()
+	os.MkdirAll(filepath.Join(dir, "cli"), 0o755)
+	os.WriteFile(filepath.Join(dir, "cli", "dev-work.md"), []byte("---\ntitle: Dev Work\ntags: [cli, dev]\n---\n\n## Usage\n\ncore dev work syncs your workspace.\n"), 0o644)
+	os.WriteFile(filepath.Join(dir, "cli", "setup.md"), []byte("---\ntitle: Setup\ntags: [cli]\n---\n\n## Installation\n\nRun core setup to get started.\n"), 0o644)
+
+	catalog, err := LoadContentDir(dir)
+	require.NoError(t, err)
+	assert.Len(t, catalog.List(), 2)
+
+	devWork, err := catalog.Get("dev-work")
+	require.NoError(t, err)
+	assert.Equal(t, "Dev Work", devWork.Title)
+	assert.Contains(t, devWork.Tags, "cli")
+
+	results := catalog.Search("workspace")
+	assert.NotEmpty(t, results)
+}
+
+func TestCatalog_LoadContentDir_Good_Empty(t *testing.T) {
+	dir := t.TempDir()
+	catalog, err := LoadContentDir(dir)
+	require.NoError(t, err)
+	assert.Empty(t, catalog.List())
+}
+
+func TestCatalog_LoadContentDir_Good_SkipsNonMd(t *testing.T) {
+	dir := t.TempDir()
+	os.WriteFile(filepath.Join(dir, "readme.txt"), []byte("not markdown"), 0o644)
+	os.WriteFile(filepath.Join(dir, "topic.md"), []byte("---\ntitle: Topic\n---\n\nContent here.\n"), 0o644)
+
+	catalog, err := LoadContentDir(dir)
+	require.NoError(t, err)
+	assert.Len(t, catalog.List(), 1)
+}
+
 func BenchmarkSearch(b *testing.B) {
 	// Build a catalog with 100+ topics for benchmarking.
 	c := &Catalog{