release: v1.3.1 — decouple plugins, CSS list/background, selection perf, demo polish

[vietnguyentuan2019]

Summary

• Decouple native deps: hyper_render_clipboard and hyper_render_math removed from root hyper_render defaults — eliminates Android compileSdk = 34 requirement for basic users; both are now opt-in add-ons
• New CSS: list-style-type (11 values), list-style-position, list-style shorthand, background-repeat, background-position
• Selection perf: getSelectionRects() cached (1× per drag event instead of 3×); auto-scroll speed proportional; HyperTeardropHandlePainter deduplicated and exported from core
• Edge-to-edge images: _kImageMargin = 0.0 — width: 100% images truly fill container
• Release prep: all 7 sub-package CHANGELOGs updated with [1.3.1] entries, ecosystem cross-link tables added to all READMEs, migration guide updated, prepare_publish.sh version fix
• Demo polish: padding fixes, WCAG AA contrast fixes, scroll wrappers for manga tabs, new zero_padding_image_demo

⚠️ Migration (1.3.0 → 1.3.1)

If you use SuperClipboardHandler or MathNodePlugin, add the packages explicitly:

dependencies:
  hyper_render: ^1.3.1
  hyper_render_clipboard: ^1.3.1   # opt-in
  hyper_render_math: ^1.3.1        # opt-in

Test plan

• flutter test test/ packages/hyper_render_core/test/ packages/hyper_render_html/test/ --exclude-tags golden passes (1 646 tests)
• flutter analyze — no issues
• Example app: demo pages scroll correctly, images have proper padding, colors pass contrast check
• ./scripts/prepare_publish.sh dry-run completes successfully

[github-actions]

✅ Layout Regression — All fixtures within 60 FPS budget

	Fixture	Budget (ms)	Median (ms)	P95 (ms)
❌	simple_paragraph	8	17	25
❌	mixed_inline	10	12	13
❌	float_layout	12	13	19
❌	table_20_rows	14	37	58
✅	cjk_ruby	14	9	10
❌	large_article	16	33	57

One or more fixtures exceeded the 16 ms budget.

Flutter 3.41.5 · ubuntu-22.04

No action required.

[github-actions]

❌ Visual Regression Detected

23 golden test(s) failed on Flutter 3.41.5 / ubuntu-22.04.

The rendered output no longer matches the reference images.

If the change is intentional, regenerate the goldens on the
same platform via the Update Goldens workflow dispatch, or run
locally in Docker:

docker run --rm \
  -v $(pwd):/workspace -w /workspace \
  ghcr.io/cirruslabs/flutter:3.41.5 \
  bash -c "apt-get update -qq && \
    apt-get install -y fonts-noto fonts-noto-cjk fonts-roboto && \
    flutter pub get && \
    flutter test test/golden/ --update-goldens"
git add test/golden/goldens/
git commit -m "chore: update golden references (Flutter 3.41.5)"

⚠️ Always regenerate goldens on ubuntu-22.04 with Flutter
3.41.5 to keep references pixel-stable across machines.

[github-actions]

✅ Layout Regression — All fixtures within 60 FPS budget

	Fixture	Budget (ms)	Median (ms)	P95 (ms)
❌	simple_paragraph	8	17	21
❌	mixed_inline	10	16	21
❌	float_layout	12	19	24
❌	table_20_rows	14	46	67
✅	cjk_ruby	14	10	11
❌	large_article	16	36	51

One or more fixtures exceeded the 16 ms budget.

Flutter 3.41.5 · ubuntu-22.04

No action required.

[github-actions]

❌ Visual Regression Detected

23 golden test(s) failed on Flutter 3.41.5 / ubuntu-22.04.

The rendered output no longer matches the reference images.

If the change is intentional, regenerate the goldens on the
same platform via the Update Goldens workflow dispatch, or run
locally in Docker:

docker run --rm \
  -v $(pwd):/workspace -w /workspace \
  ghcr.io/cirruslabs/flutter:3.41.5 \
  bash -c "apt-get update -qq && \
    apt-get install -y fonts-noto fonts-noto-cjk fonts-roboto && \
    flutter pub get && \
    flutter test test/golden/ --update-goldens"
git add test/golden/goldens/
git commit -m "chore: update golden references (Flutter 3.41.5)"

⚠️ Always regenerate goldens on ubuntu-22.04 with Flutter
3.41.5 to keep references pixel-stable across machines.