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>

blog/bp/fragments/routes.py

@@ -28,32 +28,86 @@ def register():
         if handler is None:
             return Response("", status=200, content_type="text/sexp")
         result = await handler()
-        # nav-tree still returns HTML (Jinja template) for now
-        ct = "text/html" if fragment_type == "nav-tree" else "text/sexp"
-        return Response(result, status=200, content_type=ct)
+        return Response(result, status=200, content_type="text/sexp")
 
-    # --- nav-tree fragment (still Jinja for now — complex template) ---
+    # --- nav-tree fragment — returns sexp source ---
     async def _nav_tree_handler():
+        from shared.sexp.helpers import sexp_call, SexpExpr
+        from shared.infrastructure.urls import (
+            blog_url, cart_url, market_url, events_url,
+            federation_url, account_url, artdag_url,
+        )
+
         app_name = request.args.get("app_name", "")
         path = request.args.get("path", "/")
         first_seg = path.strip("/").split("/")[0]
         menu_items = list(await get_navigation_tree(g.s))
 
-        class _NavItem:
-            __slots__ = ("slug", "label", "feature_image")
-            def __init__(self, slug, label, feature_image=None):
-                self.slug = slug
-                self.label = label
-                self.feature_image = feature_image
+        app_slugs = {
+            "cart": cart_url("/"),
+            "market": market_url("/"),
+            "events": events_url("/"),
+            "federation": federation_url("/"),
+            "account": account_url("/"),
+            "artdag": artdag_url("/"),
+        }
 
-        menu_items.append(_NavItem("artdag", "art-dag"))
+        nav_cls = "whitespace-nowrap flex items-center gap-2 rounded p-2 text-sm"
 
-        return await render_template(
-            "fragments/nav_tree.html",
-            menu_items=menu_items,
-            frag_app_name=app_name,
-            frag_first_seg=first_seg,
-        )
+        item_sexps = []
+        for item in menu_items:
+            href = app_slugs.get(item.slug, blog_url(f"/{item.slug}/"))
+            selected = "true" if (item.slug == first_seg
+                                  or item.slug == app_name) else "false"
+            img = sexp_call("blog-nav-item-image",
+                            src=getattr(item, "feature_image", None),
+                            label=getattr(item, "label", item.slug))
+            item_sexps.append(sexp_call(
+                "blog-nav-item-plain",
+                href=href, selected=selected, nav_cls=nav_cls,
+                img=SexpExpr(img), label=getattr(item, "label", item.slug),
+            ))
+
+        # artdag link
+        href = artdag_url("/")
+        selected = "true" if ("artdag" == first_seg
+                              or "artdag" == app_name) else "false"
+        img = sexp_call("blog-nav-item-image", src=None, label="art-dag")
+        item_sexps.append(sexp_call(
+            "blog-nav-item-plain",
+            href=href, selected=selected, nav_cls=nav_cls,
+            img=SexpExpr(img), label="art-dag",
+        ))
+
+        if not item_sexps:
+            return sexp_call("blog-nav-empty",
+                             wrapper_id="menu-items-nav-wrapper")
+
+        items_frag = "(<> " + " ".join(item_sexps) + ")"
+
+        arrow_cls = "scrolling-menu-arrow-menu-items-container"
+        container_id = "menu-items-container"
+        left_hs = ("on click set #" + container_id
+                    + ".scrollLeft to #" + container_id + ".scrollLeft - 200")
+        scroll_hs = ("on scroll "
+                     "set cls to '" + arrow_cls + "' "
+                     "set arrows to document.getElementsByClassName(cls) "
+                     "set show to (window.innerWidth >= 640 and "
+                     "my.scrollWidth > my.clientWidth) "
+                     "repeat for arrow in arrows "
+                     "if show remove .hidden from arrow add .flex to arrow "
+                     "else add .hidden to arrow remove .flex from arrow end "
+                     "end")
+        right_hs = ("on click set #" + container_id
+                     + ".scrollLeft to #" + container_id + ".scrollLeft + 200")
+
+        return sexp_call("blog-nav-wrapper",
+                         arrow_cls=arrow_cls,
+                         container_id=container_id,
+                         left_hs=left_hs,
+                         scroll_hs=scroll_hs,
+                         right_hs=right_hs,
+                         items=SexpExpr(items_frag))
 
     _handlers["nav-tree"] = _nav_tree_handler