fix(gallery): render answer_html so card previews match the share page

Gallery was reading the plain answer field and HTML-escaping it,
showing literal `<ol>...` text where the actual share page rendered
the markdown. Now selects answer_html alongside, runs it through
the same sanitizer as the share-card render, and falls back to
escaped plaintext for legacy rows.

migrations/20260502173044_share_cards_answer_html.sql

@@ -0,0 +1,18 @@
+-- 20260502173044_share_cards_answer_html.sql
+--
+-- Adds answer_html (nullable text) to public.share_cards so the gallery
+-- /said preview can render the same marked.js-produced HTML that the
+-- /share/<id> page already renders. Without this, gallery cards
+-- HTML-escape the plaintext answer and show literal angle-bracket text
+-- where the share page shows formatted lists, bold, code blocks, etc.
+--
+-- Nullable on purpose: existing rows pre-share-redesign have no rendered
+-- HTML captured. The /said handler falls back to escaping the plain
+-- answer field for those legacy rows.
+--
+-- Applied out-of-band via the Supabase Management API
+-- (POST /v1/projects/<ref>/database/query). This file lands the change
+-- in version control as the canonical record.
+
+alter table public.share_cards
+  add column if not exists answer_html text;