Externalize sexp to .sexpr files + render() API

Replace all 676 inline sexp() string calls across 7 services with
render(component_name, **kwargs) calls backed by 46 external .sexpr
component definition files (587 defcomps total).

- Add render() function to shared/sexp/jinja_bridge.py
- Add load_service_components() helper and update load_sexp_dir() for *.sexpr
- Update parser keyword regex to support HTMX hx-on::event syntax
- Convert remaining inline HTML in route files to render() calls
- Add shared/sexp/templates/misc.sexp for cross-service utility components

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

shared/sexp/templates/misc.sexp

@@ -0,0 +1,30 @@
+;; Miscellaneous shared components for Phase 3 conversion
+
+(defcomp ~error-inline (&key message)
+  (div :class "text-red-600 text-sm" (raw! message)))
+
+(defcomp ~notification-badge (&key count)
+  (span :class "bg-red-500 text-white text-xs rounded-full px-1.5 py-0.5" (raw! count)))
+
+(defcomp ~cache-cleared (&key time-str)
+  (span :class "text-green-600 font-bold" "Cache cleared at " (raw! time-str)))
+
+(defcomp ~error-list (&key items-html)
+  (ul :class "list-disc pl-5 space-y-1 text-sm text-red-600"
+    (raw! items-html)))
+
+(defcomp ~error-list-item (&key message)
+  (li (raw! message)))
+
+(defcomp ~fragment-error (&key service)
+  (p :class "text-sm text-red-600" "Service " (b (raw! service)) " is unavailable."))
+
+(defcomp ~htmx-sentinel (&key id hx-get hx-trigger hx-swap class extra-attrs)
+  (div :id id :hx-get hx-get :hx-trigger hx-trigger :hx-swap hx-swap :class class))
+
+(defcomp ~nav-group-link (&key href hx-select nav-class label)
+  (div :class "relative nav-group"
+    (a :href href :hx-get href :hx-target "#main-panel"
+      :hx-select hx-select :hx-swap "outerHTML"
+      :hx-push-url "true" :class nav-class
+      (raw! label))))