Convert last Python fragment handlers to SX defhandlers: 100% declarative fragment API

- Add dict recursion to _convert_result for service methods returning dict[K, list[DTO]]
- New container-cards.sx: parses post_ids/slugs, calls confirmed-entries-for-posts, emits card-widget markers
- New account-page.sx: dispatches on slug for tickets/bookings panels with status pills and empty states
- Fix blog _parse_card_fragments to handle SxExpr via str() cast
- Remove events Python fragment handlers and simplify app.py to plain auto_mount

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

blog/bp/blog/services/posts_data.py

@@ -126,7 +126,7 @@ _CARD_MARKER_RE = re.compile(
 def _parse_card_fragments(html: str) -> dict[str, str]:
     """Parse the container-cards fragment into {post_id_str: html} dict."""
     result = {}
-    for m in _CARD_MARKER_RE.finditer(html):
+    for m in _CARD_MARKER_RE.finditer(str(html)):
         post_id_str = m.group(1)
         inner = m.group(2).strip()
         if inner: