Add global web nav with project groups and tree sidebar.

Restructure the UI into top-level tabs and a scrollable project tree, and persist optional project groups so demos and settings can organize many projects.

Co-authored-by: Cursor <cursoragent@cursor.com>

internal/server/group_handlers.go

@@ -0,0 +1,60 @@
+package server
+
+import (
+	"net/http"
+)
+
+func (s *Server) handleListGroups(w http.ResponseWriter, r *http.Request) {
+	groups, err := s.DB.ListProjectGroups()
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+	writeJSON(w, http.StatusOK, groups)
+}
+
+func (s *Server) handleCreateGroup(w http.ResponseWriter, r *http.Request) {
+	var body struct {
+		Name string `json:"name"`
+	}
+	if err := readJSON(r, &body); err != nil {
+		writeError(w, http.StatusBadRequest, "invalid json")
+		return
+	}
+	g, err := s.DB.CreateProjectGroup(body.Name)
+	if err != nil {
+		writeError(w, http.StatusBadRequest, err.Error())
+		return
+	}
+	writeJSON(w, http.StatusCreated, g)
+}
+
+func (s *Server) handlePatchGroup(w http.ResponseWriter, r *http.Request) {
+	id := r.PathValue("id")
+	var body struct {
+		Name string `json:"name"`
+	}
+	if err := readJSON(r, &body); err != nil {
+		writeError(w, http.StatusBadRequest, "invalid json")
+		return
+	}
+	if err := s.DB.RenameProjectGroup(id, body.Name); err != nil {
+		writeError(w, http.StatusBadRequest, err.Error())
+		return
+	}
+	g, err := s.DB.GetProjectGroup(id)
+	if err != nil {
+		writeError(w, http.StatusNotFound, err.Error())
+		return
+	}
+	writeJSON(w, http.StatusOK, g)
+}
+
+func (s *Server) handleDeleteGroup(w http.ResponseWriter, r *http.Request) {
+	id := r.PathValue("id")
+	if err := s.DB.DeleteProjectGroup(id); err != nil {
+		writeError(w, http.StatusBadRequest, err.Error())
+		return
+	}
+	writeJSON(w, http.StatusOK, map[string]string{"status": "ok"})
+}