feat: miller column browser, offline cache, search, breadcrumbs

- Dynamic miller column sizing with flexbox layout
- Root column (160px), middle slices (48px), active column (flex)
- Auto-scroll browser to rightmost column on navigation
- Offline indicator UI and IndexedDB cache integration
- /api/documents endpoint for client-side document caching
- Breadcrumb navigation in document content area
- FTS5 search with SQLite virtual table
- Client-side Mermaid and KaTeX rendering via CDN
- Deep sample content (advanced-topics/raft-deep-dive)
- Border removal (only search button keeps radius)
- Full viewport layout with proper borders between sidebar/content

apps/server/internal/httpserver/handlers.go

@@ -33,12 +33,18 @@ type indexData struct {
 }
 
 type documentData struct {
-	Browser browserData
-	Title   string
-	Path    string
-	Tags    []string
-	Hash    string
-	HTML    template.HTML
+	Browser     browserData
+	Title       string
+	Path        string
+	Tags        []string
+	Hash        string
+	HTML        template.HTML
+	Breadcrumbs []breadcrumb
+}
+
+type breadcrumb struct {
+	Name string
+	URL  string
 }
 
 type errorData struct {
@@ -66,6 +72,12 @@ type browserItem struct {
 }
 
 func (s *Server) handleIndex(w http.ResponseWriter, r *http.Request) {
+	query := r.URL.Query().Get("q")
+	if query != "" {
+		s.handleSearchPage(w, r, query)
+		return
+	}
+
 	items, err := s.documents.ListDocuments(r.Context())
 	if err != nil {
 		s.renderError(w, r, http.StatusInternalServerError, err.Error())
@@ -84,6 +96,30 @@ func (s *Server) handleIndex(w http.ResponseWriter, r *http.Request) {
 	})
 }
 
+func (s *Server) handleSearchPage(w http.ResponseWriter, r *http.Request, query string) {
+	ctx, cancel := context.WithTimeout(r.Context(), 5*time.Second)
+	defer cancel()
+
+	results, err := s.repository.SearchDocuments(ctx, query)
+	if err != nil {
+		s.logger.Warn("search failed", "error", err)
+	}
+
+	s.renderTemplate(w, http.StatusOK, "search.gohtml", layoutData{
+		Title:        "Search: " + query,
+		WebEnabled:   s.webEnabled,
+		BodyClass:    "page-search",
+		BodyTemplate: "search_content",
+		Data: struct {
+			Query   string
+			Results []docs.SearchResult
+		}{
+			Query:   query,
+			Results: results,
+		},
+	})
+}
+
 func (s *Server) handleDocsIndex(w http.ResponseWriter, r *http.Request) {
 	s.renderDocumentPage(w, r, "")
 }
@@ -116,12 +152,13 @@ func (s *Server) renderDocumentPage(w http.ResponseWriter, r *http.Request, page
 		BodyClass:    "page-document",
 		BodyTemplate: "document_content",
 		Data: documentData{
-			Browser: buildBrowser(items, page.Path),
-			Title:   page.Title,
-			Path:    page.Path,
-			Tags:    page.Tags,
-			Hash:    page.Hash,
-			HTML:    template.HTML(page.HTML),
+			Browser:     buildBrowser(items, page.Path),
+			Title:       page.Title,
+			Path:        page.Path,
+			Tags:        page.Tags,
+			Hash:        page.Hash,
+			HTML:        template.HTML(page.HTML),
+			Breadcrumbs: buildBreadcrumbs(page.Path),
 		},
 	})
 }
@@ -147,6 +184,26 @@ func (s *Server) handleHealth(w http.ResponseWriter, r *http.Request) {
 	})
 }
 
+func (s *Server) handleSearch(w http.ResponseWriter, r *http.Request) {
+	query := r.URL.Query().Get("q")
+	if query == "" {
+		writeJSON(w, http.StatusOK, map[string]interface{}{"results": []any{}})
+		return
+	}
+
+	ctx, cancel := context.WithTimeout(r.Context(), 5*time.Second)
+	defer cancel()
+
+	results, err := s.repository.SearchDocuments(ctx, query)
+	if err != nil {
+		s.logger.Warn("search failed", "error", err)
+		writeJSON(w, http.StatusOK, map[string]interface{}{"results": []any{}})
+		return
+	}
+
+	writeJSON(w, http.StatusOK, map[string]interface{}{"results": results})
+}
+
 func (s *Server) handleUpload(w http.ResponseWriter, r *http.Request) {
 	if err := r.ParseMultipartForm(32 << 20); err != nil {
 		s.renderError(w, r, http.StatusBadRequest, "invalid multipart upload")
@@ -264,6 +321,25 @@ func sanitizeFilename(name string) string {
 	return strings.ReplaceAll(name, "\"", "")
 }
 
+func (s *Server) handleDocuments(w http.ResponseWriter, r *http.Request) {
+	records, err := s.documents.ListDocuments(r.Context())
+	if err != nil {
+		writeJSON(w, http.StatusInternalServerError, map[string]string{"error": err.Error()})
+		return
+	}
+
+	results := make([]map[string]any, 0, len(records))
+	for _, record := range records {
+		results = append(results, map[string]any{
+			"path":  record.Path,
+			"title": record.Title,
+			"hash":  record.CurrentHash,
+		})
+	}
+
+	writeJSON(w, http.StatusOK, map[string]any{"documents": results})
+}
+
 func writeJSON(w http.ResponseWriter, status int, payload any) {
 	writeJSONWithStatus(w, status, payload)
 }
@@ -424,3 +500,32 @@ func shouldHideIndexFile(path string, prefix string) bool {
 	folder := strings.TrimSuffix(path, "/index.md")
 	return folder == prefix
 }
+
+func buildBreadcrumbs(path string) []breadcrumb {
+	crumbs := []breadcrumb{
+		{Name: "Content", URL: "/"},
+	}
+	if path == "" {
+		return crumbs
+	}
+
+	cleanPath := strings.TrimSuffix(path, "/index.md")
+	cleanPath = strings.TrimSuffix(cleanPath, ".md")
+	parts := strings.Split(cleanPath, "/")
+	currentPath := ""
+	for _, part := range parts {
+		if part == "" {
+			continue
+		}
+		if currentPath == "" {
+			currentPath = part
+		} else {
+			currentPath = currentPath + "/" + part
+		}
+		crumbs = append(crumbs, breadcrumb{
+			Name: part,
+			URL:  "/docs/" + currentPath,
+		})
+	}
+	return crumbs
+}