fix: HTML reports drop imbalance/missing/skew meta line and reference section

assets/profiler-ui.js

@@ -497,10 +497,26 @@
           '<td class="num">' + g.count.toLocaleString() + '</td>' +
           '<td class="bar"><span style="width:' + (g.share * 100).toFixed(1) + '%"></span></td></tr>';
       }).join('');
+
+      var referenceHtml = '';
+      if (d.reference) {
+        var refRows = d.reference.groups.slice(0, DISPLAY_GROUPS).map(function (g) {
+          return '<tr><td>' + esc(g.label) + '</td>' +
+            '<td class="num">' + (g.expected * 100).toFixed(1) + '%</td>' +
+            '<td class="num">' + (g.actual * 100).toFixed(1) + '%</td>' +
+            '<td class="num">' + (g.delta > 0 ? '+' : '') + (g.delta * 100).toFixed(1) + ' pp</td></tr>';
+        }).join('');
+        referenceHtml = '<div class="reference"><h3>Reference ' +
+          '<span class="kind">deviation ' + (d.reference.deviation * 100).toFixed(1) + '%</span></h3>' +
+          '<table><tr><th></th><th class="num">Expected</th>' +
+          '<th class="num">Actual</th><th class="num">Delta</th></tr>' +
+          refRows + '</table></div>';
+      }
+
       return '<section class="dim"><h2>' + esc(d.name) +
         ' <span class="kind">' + esc(d.kind) + '</span> ' +
         '<span class="score">' + d.dimension_score + '/100</span></h2>' +
-        '<table>' + rows + '</table></section>';
+        '<table>' + rows + '</table>' + referenceHtml + '</section>';
     }).join('');
 
     var flagHtml = '';
@@ -530,6 +546,10 @@
       ' tr.under td.bar span { background:var(--accent); }\n' +
       ' tr.under td:first-child::after { content:\' (under-represented)\'; color:var(--accent); font-size:11px; }\n' +
       ' tr.small-group td:first-child::before { content:\'⚠ small group \'; color:var(--accent); }\n' +
+      ' .reference { margin-top:10px; padding-top:10px; border-top:1px dashed var(--border); }\n' +
+      ' .reference h3 { font-size:.75em; margin:0 0 6px; }\n' +
+      ' .reference th { text-align:right; font-size:11px; color:var(--muted); font-weight:normal; }\n' +
+      ' .reference th:first-child { text-align:left; }\n' +
       ' .flags ul { list-style:none; padding:0; }\n' +
       ' .flags li { background:#fbeae3; border-left:3px solid var(--accent); padding:8px 12px; margin:6px 0; border-radius:0 4px 4px 0; }\n' +
       ' .head { border-bottom:2px solid var(--accent); padding-bottom:12px; }\n' +

faircode/report.py

@@ -197,10 +197,24 @@ def esc(s) -> str:
                 f'{ref_rows}</table></div>'
             )
 
+        meta_parts = []
+        if d["imbalance_ratio"] is not None:
+            meta_parts.append(f"imbalance {d['imbalance_ratio']:.1f}x")
+        elif d["n_groups"] > 1:
+            meta_parts.append("imbalance inf (empty subgroup)")
+        if d["missing_pct"] > 0:
+            meta_parts.append(f"missing {d['missing_pct'] * 100:.1f}%")
+        if d["skewness"] is not None:
+            meta_parts.append(f"skew {d['skewness']:+.2f}")
+        meta_html = (
+            f' <span class="meta">({esc("  ".join(meta_parts))})</span>'
+            if meta_parts else ""
+        )
+
         dim_blocks.append(
             f'<section class="dim"><h2>{esc(d["name"])} '
             f'<span class="kind">{esc(d["kind"])}</span> '
-            f'<span class="score">{d["dimension_score"]}/100</span></h2>'
+            f'<span class="score">{d["dimension_score"]}/100</span>{meta_html}</h2>'
             f'<table><caption>Group breakdown - {esc(d["name"])}</caption>'
             f'<thead><tr><th scope="col">Group</th><th scope="col" class="num">Share</th>'
             f'<th scope="col" class="num">95% CI</th><th scope="col" class="num">Count</th>'
@@ -238,6 +252,7 @@ def esc(s) -> str:
  h1 {{ font-family:Georgia,serif; }}
  .score {{ color:var(--accent3); font-size:.7em; font-weight:600; }}
  .kind {{ color:var(--muted); font-size:.6em; text-transform:uppercase; letter-spacing:.08em; }}
+ .meta {{ color:var(--muted); font-size:.6em; }}
  .dim {{ background:var(--surface); border:1px solid var(--border); border-radius:8px;
          padding:16px 20px; margin:16px 0; }}
  table {{ width:100%; border-collapse:collapse; }}

tests/test_report.py

@@ -86,6 +86,9 @@ def test_to_html_renders_key_figures(mock_profile_result):
     assert "88/100" in html_out
     assert "B+" in html_out
     assert "Gender" in html_out
+    assert "imbalance 1.6x" in html_out
+    assert "missing 2.0%" in html_out
+    assert "skew +0.30" in html_out
 
 
 def test_to_html_renders_proxy_hints(mock_profile_result):