Fix sx docs pages leaking raw s-expressions and missing sub-row

Three issues fixed:

- async_eval_slot_to_sx (and async_eval_to_sx) was calling serialize()
  on plain strings returned by page helpers, quoting them as literals
  instead of treating them as sx source. Added str check to wrap
  directly in SxExpr.

- _render_to_sx_with_env passed layout kwargs only as env free
  variables, but _aser_component defaults all declared params to NIL
  regardless of env. Now builds the AST with extra_env entries as
  keyword args so they bind through normal param mechanism.

- _nav_items_sx returned plain str; changed to SxExpr so nav fragments
  serialize unquoted when passed as layout kwargs.

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

shared/sx/async_eval.py

@@ -1013,6 +1013,8 @@ async def async_eval_to_sx(
         return result
     if result is None or result is NIL:
         return SxExpr("")
+    if isinstance(result, str):
+        return SxExpr(result)
     return SxExpr(serialize(result))
 
 
@@ -1042,6 +1044,8 @@ async def async_eval_slot_to_sx(
                     return result
                 if result is None or result is NIL:
                     return SxExpr("")
+                if isinstance(result, str):
+                    return SxExpr(result)
                 return SxExpr(serialize(result))
             else:
                 import logging
@@ -1059,6 +1063,9 @@ async def async_eval_slot_to_sx(
         return result
     if result is None or result is NIL:
         return SxExpr("")
+    if isinstance(result, str):
+        # Plain strings from page helpers are already sx source — don't quote.
+        return SxExpr(result)
     return SxExpr(serialize(result))
 
 

shared/sx/helpers.py

@@ -347,8 +347,19 @@ async def _render_to_sx_with_env(__name: str, extra_env: dict, **kwargs: Any) ->
     """
     from .jinja_bridge import get_component_env, _get_request_context
     from .async_eval import async_eval_slot_to_sx
+    from .types import Symbol, Keyword, NIL as _NIL
+
+    # Build AST with extra_env entries as keyword args so _aser_component
+    # binds them as params (otherwise it defaults all params to NIL).
+    comp_sym = Symbol(__name if __name.startswith("~") else f"~{__name}")
+    ast: list = [comp_sym]
+    for k, v in extra_env.items():
+        ast.append(Keyword(k))
+        ast.append(v if v is not None else _NIL)
+    for k, v in kwargs.items():
+        ast.append(Keyword(k.replace("_", "-")))
+        ast.append(v if v is not None else _NIL)
 
-    ast = _build_component_ast(__name, **kwargs)
     env = dict(get_component_env())
     env.update(extra_env)
     ctx = _get_request_context()

sx/sxc/pages/utils.py

@@ -6,7 +6,7 @@ from shared.sx.helpers import (
 )
 
 
-def _nav_items_sx(items: list[tuple[str, str]], current: str | None = None) -> str:
+def _nav_items_sx(items: list[tuple[str, str]], current: str | None = None) -> SxExpr:
     """Build nav link items as sx."""
     parts = []
     for label, href in items:
@@ -15,7 +15,7 @@ def _nav_items_sx(items: list[tuple[str, str]], current: str | None = None) -> s
             is_selected="true" if current == label else None,
             select_colours="aria-selected:bg-violet-200 aria-selected:text-violet-900",
         ))
-    return "(<> " + " ".join(parts) + ")"
+    return SxExpr("(<> " + " ".join(parts) + ")")
 
 
 def _doc_nav_sx(items: list[tuple[str, str]], current: str) -> str: