Send all responses as sexp wire format with client-side rendering

- Server sends sexp source text, client (sexp.js) renders everything
- SexpExpr marker class for nested sexp composition in serialize()
- sexp_page() HTML shell with data-mount="body" for full page loads
- sexp_response() returns text/sexp for OOB/partial responses
- ~app-body layout component replaces ~app-layout (no raw!)
- ~rich-text is the only component using raw! (for CMS HTML content)
- Fragment endpoints return text/sexp, auto-wrapped in SexpExpr
- All _*_html() helpers converted to _*_sexp() returning sexp source
- Head auto-hoist: sexp.js moves meta/title/link/script[ld+json]
  from rendered body to document.head automatically
- Unknown components render warning box instead of crashing page
- Component kwargs preserve AST for lazy rendering (fixes <> in kwargs)
- Fix unterminated paren in events/sexp/tickets.sexpr

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

account/bp/account/routes.py

@@ -18,6 +18,7 @@ from shared.models import UserNewsletter
 from shared.models.ghost_membership_entities import GhostNewsletter
 from shared.infrastructure.urls import login_url
 from shared.infrastructure.fragments import fetch_fragment, fetch_fragments
+from shared.sexp.helpers import sexp_response
 
 oob = {
     "oob_extends": "oob_elements.html",
@@ -41,7 +42,7 @@ def register(url_prefix="/"):
             ("cart", "account-nav-item", {}),
             ("artdag", "nav-item", {}),
         ], required=False)
-        return {"oob": oob, "account_nav_html": events_nav + cart_nav + artdag_nav}
+        return {"oob": oob, "account_nav": events_nav + cart_nav + artdag_nav}
 
     @account_bp.get("/")
     async def account():
@@ -55,10 +56,10 @@ def register(url_prefix="/"):
         ctx = await get_template_context()
         if not is_htmx_request():
             html = await render_account_page(ctx)
+            return await make_response(html)
         else:
-            html = await render_account_oob(ctx)
-
-        return await make_response(html)
+            sexp_src = await render_account_oob(ctx)
+            return sexp_response(sexp_src)
 
     @account_bp.get("/newsletters/")
     async def newsletters():
@@ -94,10 +95,10 @@ def register(url_prefix="/"):
         ctx = await get_template_context()
         if not is_htmx_request():
             html = await render_newsletters_page(ctx, newsletter_list)
+            return await make_response(html)
         else:
-            html = await render_newsletters_oob(ctx, newsletter_list)
-
-        return await make_response(html)
+            sexp_src = await render_newsletters_oob(ctx, newsletter_list)
+            return sexp_response(sexp_src)
 
     @account_bp.post("/newsletter/<int:newsletter_id>/toggle/")
     async def toggle_newsletter(newsletter_id: int):
@@ -125,7 +126,7 @@ def register(url_prefix="/"):
         await g.s.flush()
 
         from sexp.sexp_components import render_newsletter_toggle
-        return render_newsletter_toggle(un)
+        return sexp_response(render_newsletter_toggle(un))
 
     # Catch-all for fragment-provided pages — must be last
     @account_bp.get("/<slug>/")
@@ -149,9 +150,9 @@ def register(url_prefix="/"):
         ctx = await get_template_context()
         if not is_htmx_request():
             html = await render_fragment_page(ctx, fragment_html)
+            return await make_response(html)
         else:
-            html = await render_fragment_oob(ctx, fragment_html)
-
-        return await make_response(html)
+            sexp_src = await render_fragment_oob(ctx, fragment_html)
+            return sexp_response(sexp_src)
 
     return account_bp