Migrate all apps to defpage declarative page routes

Replace Python GET page handlers with declarative defpage definitions in .sx
files across all 8 apps (sx docs, orders, account, market, cart, federation,
events, blog). Each app now has sxc/pages/ with setup functions, layout
registrations, page helpers, and .sx defpage declarations.

Core infrastructure: add g I/O primitive, PageDef support for auth/layout/
data/content/filter/aside/menu slots, post_author auth level, and custom
layout registration. Remove ~1400 lines of render_*_page/render_*_oob
boilerplate. Update all endpoint references in routes, sx_components, and
templates to defpage_* naming.

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

blog/bp/blog/routes.py

@@ -51,10 +51,19 @@ def register(url_prefix, title):
       pass
 
     @blogs_bp.before_request
-    def route():
+    async def route():
       g.makeqs_factory = makeqs_factory
+      ep = request.endpoint or ""
+      if "defpage_new_post" in ep:
+          from sx.sx_components import render_editor_panel
+          g.editor_content = render_editor_panel()
+      elif "defpage_new_page" in ep:
+          from sx.sx_components import render_editor_panel
+          g.editor_page_content = render_editor_panel(is_page=True)
+
+    from shared.sx.pages import mount_pages
+    mount_pages(blogs_bp, "blog", names=["new-post", "new-page"])
 
-    
     @blogs_bp.context_processor
     async def inject_root():
       return {
@@ -215,21 +224,6 @@ def register(url_prefix, title):
           sx_src = await render_blog_oob(tctx)
           return sx_response(sx_src)
 
-    @blogs_bp.get("/new/")
-    @require_admin
-    async def new_post():
-      from shared.sx.page import get_template_context
-      from sx.sx_components import render_new_post_page, render_new_post_oob, render_editor_panel
-
-      tctx = await get_template_context()
-      tctx["editor_html"] = render_editor_panel()
-      if not is_htmx_request():
-        html = await render_new_post_page(tctx)
-        return await make_response(html)
-      else:
-        sx_src = await render_new_post_oob(tctx)
-        return sx_response(sx_src)
-
     @blogs_bp.post("/new/")
     @require_admin
     async def new_post_save():
@@ -283,25 +277,9 @@ def register(url_prefix, title):
       await invalidate_tag_cache("blog")
 
       # Redirect to the edit page
-      return redirect(host_url(url_for("blog.post.admin.edit", slug=post.slug)))
+      return redirect(host_url(url_for("blog.post.admin.defpage_post_edit", slug=post.slug)))
 
 
-    @blogs_bp.get("/new-page/")
-    @require_admin
-    async def new_page():
-      from shared.sx.page import get_template_context
-      from sx.sx_components import render_new_post_page, render_new_post_oob, render_editor_panel
-
-      tctx = await get_template_context()
-      tctx["editor_html"] = render_editor_panel(is_page=True)
-      tctx["is_page"] = True
-      if not is_htmx_request():
-        html = await render_new_post_page(tctx)
-        return await make_response(html)
-      else:
-        sx_src = await render_new_post_oob(tctx)
-        return sx_response(sx_src)
-
     @blogs_bp.post("/new-page/")
     @require_admin
     async def new_page_save():
@@ -357,7 +335,7 @@ def register(url_prefix, title):
       await invalidate_tag_cache("blog")
 
       # Redirect to the page admin
-      return redirect(host_url(url_for("blog.post.admin.edit", slug=page.slug)))
+      return redirect(host_url(url_for("blog.post.admin.defpage_post_edit", slug=page.slug)))
 
 
     @blogs_bp.get("/drafts/")