SX docs: configurable shell, SX-native event handlers, nav fixes

- Configurable page shell (~sx-page-shell kwargs + SX_SHELL app config)
  so each app controls its own assets — sx docs loads only sx-browser.js
- SX-evaluated sx-on:* handlers (eval-expr instead of new Function)
  with DOM primitives registered in PRIMITIVES table
- data-init boot mode for pure SX initialization scripts
- Jiggle animation on links while fetching
- Nav: 3-column grid for centered alignment, is-leaf sizing,
  fix map-indexed param order (index, item), guard mod-by-zero
- Async route eval failure now falls back to server fetch
  instead of silently rendering nothing
- Remove duplicate h1 title from ~doc-page
- Re-bootstrap sx-ref.js + sx-browser.js

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

shared/sx/jinja_bridge.py

@@ -132,7 +132,11 @@ def watch_sx_dir(directory: str) -> None:
 
 def reload_if_changed() -> None:
     """Re-read sx files if any have changed on disk. Called per-request in dev."""
-    changed = False
+    import logging
+    import time
+    _logger = logging.getLogger("sx.reload")
+
+    changed_files = []
     for directory in _watched_dirs:
         for fp in sorted(
             glob.glob(os.path.join(directory, "**", "*.sx"), recursive=True)
@@ -140,14 +144,27 @@ def reload_if_changed() -> None:
             mtime = os.path.getmtime(fp)
             if fp not in _file_mtimes or _file_mtimes[fp] != mtime:
                 _file_mtimes[fp] = mtime
-                changed = True
-    if changed:
+                changed_files.append(fp)
+    if changed_files:
+        for fp in changed_files:
+            _logger.info("Changed: %s", fp)
+        t0 = time.monotonic()
         _COMPONENT_ENV.clear()
         # Reload SX libraries first (e.g. z3.sx) so reader macros resolve
         for cb in _reload_callbacks:
             cb()
         for directory in _watched_dirs:
             load_sx_dir(directory)
+        t1 = time.monotonic()
+        _logger.info("Reloaded %d file(s), components in %.1fms",
+                     len(changed_files), (t1 - t0) * 1000)
+
+        # Recompute render plans for all services that have pages
+        from .pages import _PAGE_REGISTRY, compute_page_render_plans
+        for svc in _PAGE_REGISTRY:
+            t2 = time.monotonic()
+            compute_page_render_plans(svc)
+            _logger.info("Render plans for %s in %.1fms", svc, (time.monotonic() - t2) * 1000)
 
 
 def load_service_components(service_dir: str, service_name: str | None = None) -> None: