Quality gates for adaptive layout:
- fill_metrics()/check_scale_up() in the safety harness: overflow catches
content too big for a panel, but nothing caught content that stays tiny
on panels >= 2x the plugin's declared design size. The check measures
lit-content extents and warns (or fails, when a plugin opts into
"fill_check": "strict" in test/harness.json) below 50% coverage on the
doubled axis. Warn-only by default so no existing plugin breaks.
- harness.json "variants": extra runs with config overlays and their own
golden dirs, so an opt-in mode (e.g. layout_mode: adaptive) is golden-
tested beside the classic default. check_plugin.py loops base + variants
and labels variant results mode@name.
- Dev preview server: GET /api/sizes (harness size sample), POST
/api/render-matrix (render at up to 12 sizes in one call), size-preset
dropdown, and an "All Sizes" side-by-side gallery in the preview UI.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
