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/dev_watcher.py

@@ -0,0 +1,69 @@
+"""Watch non-Python files and trigger Hypercorn reload.
+
+Hypercorn --reload only watches .py files.  This script watches .sexp,
+.sexpr, .js, and .css files and touches a sentinel .py file when they
+change, causing Hypercorn to restart.
+
+Usage (from entrypoint.sh, before exec hypercorn):
+    python3 -m shared.dev_watcher &
+"""
+
+import os
+import time
+import sys
+
+WATCH_EXTENSIONS = {".sexp", ".sexpr", ".js", ".css"}
+SENTINEL = os.path.join(os.path.dirname(__file__), "_reload_sentinel.py")
+POLL_INTERVAL = 1.5  # seconds
+
+
+def _collect_mtimes(roots):
+    mtimes = {}
+    for root in roots:
+        for dirpath, _dirs, files in os.walk(root):
+            for fn in files:
+                ext = os.path.splitext(fn)[1]
+                if ext in WATCH_EXTENSIONS:
+                    path = os.path.join(dirpath, fn)
+                    try:
+                        mtimes[path] = os.path.getmtime(path)
+                    except OSError:
+                        pass
+    return mtimes
+
+
+def main():
+    # Watch /app/shared and /app/<service>/sexp plus static dirs
+    roots = []
+    for entry in os.listdir("/app"):
+        full = os.path.join("/app", entry)
+        if os.path.isdir(full):
+            roots.append(full)
+    if not roots:
+        roots = ["/app"]
+
+    # Ensure sentinel exists
+    if not os.path.exists(SENTINEL):
+        with open(SENTINEL, "w") as f:
+            f.write("# reload sentinel\n")
+
+    prev = _collect_mtimes(roots)
+    while True:
+        time.sleep(POLL_INTERVAL)
+        curr = _collect_mtimes(roots)
+        changed = []
+        for path, mtime in curr.items():
+            if path not in prev or prev[path] != mtime:
+                changed.append(path)
+        if changed:
+            names = ", ".join(os.path.basename(p) for p in changed[:3])
+            if len(changed) > 3:
+                names += f" (+{len(changed) - 3} more)"
+            print(f"[dev_watcher] Changed: {names} — triggering reload",
+                  flush=True)
+            os.utime(SENTINEL, None)
+        prev = curr
+
+
+if __name__ == "__main__":
+    main()