to_html()/the web profiler's downloadable HTML report silently drops imbalance ratio, missing %, and skewness shown everywhere else

[yakew7]

Both faircode/report.py's to_html() (the --html output for faircode profile) and assets/profiler-ui.js's buildHtmlReport() (the web profiler's 'Download HTML' button) render only the group table and flags for each dimension - neither renders the per-dimension imbalance_ratio, missing_pct, or skewness fields.

Confirmed directly: to_terminal() builds a meta line ('imbalance 3.2x missing 4.0% skew +0.31') from exactly these three fields, and assets/profiler-ui.js's on-screen results view renders the identical line - but grepping both to_html() and buildHtmlReport() for imbalance_ratio/missing_pct/skewness returns nothing in either. to_json() still includes them (it's the raw profile dict), so this is specifically an HTML-rendering gap, not a data gap.

This matters because the downloadable/static HTML report is the artifact most likely to be shared with stakeholders or archived for compliance, and it's silently missing exactly the imbalance/missing-data/skew context every other view shows. tests/test_report.py's mock_profile_result fixture already sets these fields, but test_to_html_renders_key_figures never asserts they appear - which is why this has gone unnoticed.

Proposed scope: add the same 'imbalance {ratio}x missing {pct}% skew {value}' meta line already used in to_terminal()/the on-screen web UI to to_html()'s and buildHtmlReport()'s per-dimension section, and extend test_to_html_renders_key_figures to assert it appears. Good first issue: the exact string format to mirror already exists in both codebases.