Phase 5 cleanup: remove legacy HTML components, fix nav-tree fragment

- Remove old raw! layout components (~app-head, ~app-layout, ~oob-response,
  ~header-row, ~menu-row, ~oob-header, ~header-child) from layout.sexp
- Convert nav-tree fragment from Jinja HTML to sexp source, fixing the
  "Unexpected character: ." parse error caused by HTML leaking into sexp
- Add _as_sexp() helper to safely coerce HTML fragments to ~rich-text
- Fix federation/sexp/search.sexpr extra closing paren
- Remove dead _html() wrappers from blog and account sexp_components
- Remove stale render import from cart sexp_components
- Add dev_watcher.py to auto-reload on .sexp/.sexpr/.js/.css changes
- Add test_parse_all.py to parse-check all 59 sexpr/sexp files
- Fix test assertions for sx- attribute prefix (was hx-)
- Add sexp.js version logging for cache debugging

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

shared/sexp/helpers.py

@@ -36,19 +36,36 @@ def get_asset_url(ctx: dict) -> str:
 # Sexp-native helper functions — return sexp source (not HTML)
 # ---------------------------------------------------------------------------
 
+def _as_sexp(val: Any) -> SexpExpr | None:
+    """Coerce a fragment value to SexpExpr.
+
+    If *val* is already a ``SexpExpr`` (from a ``text/sexp`` fragment),
+    return it as-is.  If it's a non-empty string (HTML from a
+    ``text/html`` fragment), wrap it in ``~rich-text``.  Otherwise
+    return ``None``.
+    """
+    if not val:
+        return None
+    if isinstance(val, SexpExpr):
+        return val
+    html = str(val)
+    escaped = html.replace("\\", "\\\\").replace('"', '\\"')
+    return SexpExpr(f'(~rich-text :html "{escaped}")')
+
+
 def root_header_sexp(ctx: dict, *, oob: bool = False) -> str:
     """Build the root header row as a sexp call string."""
     rights = ctx.get("rights") or {}
     is_admin = rights.get("admin") if isinstance(rights, dict) else getattr(rights, "admin", False)
     settings_url = call_url(ctx, "blog_url", "/settings/") if is_admin else ""
     return sexp_call("header-row-sx",
-        cart_mini=ctx.get("cart_mini") and SexpExpr(str(ctx.get("cart_mini"))),
+        cart_mini=_as_sexp(ctx.get("cart_mini")),
         blog_url=call_url(ctx, "blog_url", ""),
         site_title=ctx.get("base_title", ""),
         app_label=ctx.get("app_label", ""),
-        nav_tree=ctx.get("nav_tree") and SexpExpr(str(ctx.get("nav_tree"))),
-        auth_menu=ctx.get("auth_menu") and SexpExpr(str(ctx.get("auth_menu"))),
-        nav_panel=ctx.get("nav_panel") and SexpExpr(str(ctx.get("nav_panel"))),
+        nav_tree=_as_sexp(ctx.get("nav_tree")),
+        auth_menu=_as_sexp(ctx.get("auth_menu")),
+        nav_panel=_as_sexp(ctx.get("nav_panel")),
         settings_url=settings_url,
         is_admin=is_admin,
         oob=oob,
@@ -285,19 +302,6 @@ def sexp_response(source_or_component: str, status: int = 200,
     return resp
 
 
-def oob_page(ctx: dict, *, oobs_html: str = "",
-             filter_html: str = "", aside_html: str = "",
-             content_html: str = "", menu_html: str = "") -> str:
-    """Render an OOB response with standard swap targets."""
-    return render(
-        "oob-response",
-        oobs_html=oobs_html,
-        filter_html=filter_html,
-        aside_html=aside_html,
-        menu_html=menu_html,
-        content_html=content_html,
-    )
-
 
 # ---------------------------------------------------------------------------
 # Sexp wire-format full page shell