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/tests/test_parse_all.py

@@ -0,0 +1,35 @@
+"""Verify every .sexpr and .sexp file in the repo parses without errors."""
+
+import os
+import pytest
+
+from shared.sexp.parser import parse_all
+
+
+def _collect_sexp_files():
+    """Find all .sexpr and .sexp files under the repo root."""
+    repo = os.path.dirname(os.path.dirname(os.path.dirname(os.path.dirname(
+        os.path.abspath(__file__)
+    ))))
+    files = []
+    for dirpath, _dirs, filenames in os.walk(repo):
+        if "node_modules" in dirpath or ".git" in dirpath or "artdag" in dirpath:
+            continue
+        for fn in filenames:
+            if fn.endswith((".sexpr", ".sexp")):
+                files.append(os.path.join(dirpath, fn))
+    return sorted(files)
+
+
+_SEXP_FILES = _collect_sexp_files()
+
+
+@pytest.mark.parametrize("path", _SEXP_FILES, ids=[
+    os.path.relpath(p) for p in _SEXP_FILES
+])
+def test_parse(path):
+    """Each sexp file should parse without errors."""
+    with open(path) as f:
+        source = f.read()
+    exprs = parse_all(source)
+    assert len(exprs) > 0, f"{path} produced no expressions"