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>

events/bp/calendar_entries/routes.py

@@ -16,6 +16,7 @@ from .services.entries import (
 )
 from shared.browser.app.authz import require_admin
 from shared.browser.app.redis_cacher import clear_cache
+from shared.sexp.helpers import sexp_response
 
 
 from bp.calendar_entry.routes import register as register_calendar_entry
@@ -260,7 +261,7 @@ def register():
         from sexp.sexp_components import render_day_main_panel
         html = render_day_main_panel(ctx)
         mini_html = await fetch_fragment("cart", "cart-mini", params=frag_params, required=False)
-        return await make_response(html + mini_html, 200)
+        return sexp_response(html + (mini_html or ""))
     
     @bp.get("/add/")
     async def add_form(day: int, month: int, year: int, **kwargs):