refactor: move studio to frontends workspace

- Move studio from root to frontends/studio/
- Add owner-tools frontend for live blog admin UI
- Add shared ui component library
- Set up npm workspaces for frontends
- Add enhanced code block extension for editor

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

frontends/studio/embed.go

@@ -0,0 +1,22 @@
+//go:build !testing
+
+package studio
+
+import (
+	"embed"
+	"io/fs"
+	"net/http"
+	"path"
+)
+
+//go:embed dist/*
+var distFS embed.FS
+
+func Handler() http.Handler {
+	sub, _ := fs.Sub(distFS, "dist")
+	return http.FileServer(http.FS(sub))
+}
+
+func Read(name string) ([]byte, error) {
+	return distFS.ReadFile(path.Join("dist", name))
+}