Fix services.get() → services.blog_page attribute access

The service registry uses __getattr__, so .get() is interpreted
as looking up a service named "get". Use attribute access instead.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

blog/bp/post/routes.py

@@ -122,7 +122,7 @@ def register():
     rights = tctx.get("rights") or {}
     blog_url_base = host_url(url_for("blog.index")).rstrip("/index").rstrip("/")
     csrf = generate_csrf_token()
-    svc = services.get("blog_page")
+    svc = services.blog_page
     detail_data = svc.post_detail_data(post, user, rights, csrf, blog_url_base)
     content = await render_to_sx("blog-post-detail-content", **detail_data)
     meta_data = svc.post_meta_data(post, tctx.get("base_title", ""))