feat(server): add owner-tools injection and inline code theme CSS

- Add owner-tools serving and injection for blog owners
- Inline code theme CSS in templates for soft reload support
- Update import paths from github.com/writekitapp to writekit
- Add optional session middleware for owner detection
- Update platform index with improved UI

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

internal/server/blog.go

@@ -16,13 +16,13 @@ import (
 	"time"
 
 	"github.com/go-chi/chi/v5"
-	"github.com/writekitapp/writekit/internal/auth"
-	"github.com/writekitapp/writekit/internal/build/assets"
-	"github.com/writekitapp/writekit/internal/build/templates"
-	"github.com/writekitapp/writekit/internal/config"
-	"github.com/writekitapp/writekit/internal/markdown"
-	"github.com/writekitapp/writekit/internal/tenant"
-	"github.com/writekitapp/writekit/studio"
+	"writekit/internal/auth"
+	"writekit/internal/tenant/assets"
+	"writekit/internal/tenant/templates"
+	"writekit/internal/config"
+	"writekit/internal/markdown"
+	"writekit/internal/tenant"
+	"writekit/frontends/studio"
 )
 
 func (s *Server) serveBlog(w http.ResponseWriter, r *http.Request, subdomain string) {
@@ -59,12 +59,14 @@ func (s *Server) serveBlog(w http.ResponseWriter, r *http.Request, subdomain str
 	r = r.WithContext(ctx)
 
 	mux := chi.NewRouter()
+	mux.Use(auth.OptionalSessionMiddleware(s.database))
 
 	mux.Get("/", s.blogHome)
 	mux.Get("/posts", s.blogList)
 	mux.Get("/posts/{slug}", s.blogPost)
 
 	mux.Handle("/static/*", http.StripPrefix("/static/", assets.Handler()))
+	mux.Handle("/@owner-tools/*", http.HandlerFunc(s.serveOwnerTools))
 
 	mux.Route("/api/studio", func(r chi.Router) {
 		r.Use(demoAwareSessionMiddleware(s.database))
@@ -638,8 +640,20 @@ func computeETag(data []byte) string {
 }
 
 func (s *Server) servePreRendered(w http.ResponseWriter, r *http.Request, html []byte, etag, cacheControl string) {
+	tenantID, _ := r.Context().Value(tenantIDKey).(string)
+	modified := false
+
 	if demoInfo := GetDemoInfo(r); demoInfo.IsDemo {
 		html = s.injectDemoBanner(html, demoInfo.ExpiresAt)
+		modified = true
+	}
+
+	if s.isOwner(r, tenantID) {
+		html = s.injectOwnerTools(html)
+		modified = true
+	}
+
+	if modified {
 		etag = computeETag(html)
 	}
 
@@ -701,3 +715,49 @@ func timeOrZero(t *time.Time) time.Time {
 	}
 	return *t
 }
+
+func (s *Server) isOwner(r *http.Request, tenantID string) bool {
+	if GetDemoInfo(r).IsDemo {
+		return true
+	}
+	userID := auth.GetUserID(r)
+	if userID == "" {
+		return false
+	}
+	isOwner, err := s.database.IsUserTenantOwner(r.Context(), userID, tenantID)
+	if err != nil {
+		return false
+	}
+	return isOwner
+}
+
+func (s *Server) injectOwnerTools(html []byte) []byte {
+	var script string
+	if s.ownerToolsURL != "" {
+		script = `<script type="module" src="/@owner-tools/src/main.tsx"></script>`
+	} else {
+		script = `<script src="/static/js/owner-tools.js"></script>`
+	}
+	return bytes.Replace(html, []byte("</body>"), []byte(script+"</body>"), 1)
+}
+
+func (s *Server) serveOwnerTools(w http.ResponseWriter, r *http.Request) {
+	if s.ownerToolsURL == "" {
+		http.NotFound(w, r)
+		return
+	}
+
+	target, err := url.Parse(s.ownerToolsURL)
+	if err != nil {
+		http.Error(w, "internal error", http.StatusInternalServerError)
+		return
+	}
+
+	proxy := httputil.NewSingleHostReverseProxy(target)
+	proxy.Director = func(req *http.Request) {
+		req.URL.Scheme = target.Scheme
+		req.URL.Host = target.Host
+		req.Host = target.Host
+	}
+	proxy.ServeHTTP(w, r)
+}