Rebrand sexp → sx across web platform (173 files)

Rename all sexp directories, files, identifiers, and references to sx.
artdag/ excluded (separate media processing DSL).

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

events/bp/calendar_entries/routes.py

@@ -16,7 +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 shared.sx.helpers import sx_response
 
 
 from bp.calendar_entry.routes import register as register_calendar_entry
@@ -217,7 +217,7 @@ def register():
         if ident["session_id"] is not None:
             frag_params["session_id"] = ident["session_id"]
 
-        # Re-query day entries for the sexp component
+        # Re-query day entries for the sx component
         from datetime import date as date_cls, timedelta
         from bp.calendar.services import get_visible_entries_for_period
         from quart import session as qsession
@@ -258,10 +258,10 @@ def register():
             "styles": styles,
         }
 
-        from sexp.sexp_components import render_day_main_panel
+        from sx.sx_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 sexp_response(html + (mini_html or ""))
+        return sx_response(html + (mini_html or ""))
     
     @bp.get("/add/")
     async def add_form(day: int, month: int, year: int, **kwargs):