Give Blogger tables inline borders

Blogger themes ship no table styling, so the quote tables rendered as
borderless text. Inline styles survive every theme and the mobile view.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

tests/test_blogger.py

@@ -91,7 +91,10 @@ def test_briefing_html_drops_h1_and_renders_tables():
     assert "미국 마감 브리핑 — 2026-09-01" not in html  # H1 is the post title, not body
     assert "<h2>총평</h2>" in html
     assert "<strong>하락 마감</strong>" in html
-    assert "<table>" in html and "<td>7,686.42</td>" in html
+    # tables carry inline borders - Blogger themes style nothing themselves
+    assert '<table style="border-collapse:collapse' in html
+    assert ">7,686.42</td>" in html and 'border:1px solid #ccc' in html
+    assert "<table>" not in html and "<td>" not in html  # every cell got the inline style
 
 
 def test_post_title_with_and_without_headline():