Prevent web checkout lifecycle events from bubbling

[markmur]

Checkout lifecycle events currently bubble to ancestor listeners, which can trigger unrelated handlers for generic event names such as close and update.

Set bubbles: false for start, update, complete, close, and blocked, matching the existing error event. Consumers must attach listeners directly to <shopify-checkout>; delegated bubbling listeners on ancestors or document will no longer receive these events.

Update the lifecycle documentation and existing blocked-event propagation test to match.

[github-actions]

Coverage Report

Status	Platform / target	Lines	Branches	Functions	Report
✅	Web	98%	86.6%	97.44%	Full report
⏭️	React Native	—	—	—	Not run for this change
⏭️	Embedded Checkout Protocol (TS)	—	—	—	Not run for this change

[bitrise]

Bitrise builds

E2E · iOS CI

Checkout Kit E2E results

No native E2E runs were selected for this change.

[github-actions]

Bundle Size Budgets

Budget	Size	Limits	Result
Web JavaScript (uncompressed)	35.81 KiB (0 B)	35 KiB soft / 50 KiB hard	➖ Above budget; no increase

Bundle and package size

Web bundle sizes cover shipped runtime JavaScript. Package sizes cover the full published archive, including any source maps, declarations, and documentation it contains.

Platform	Measurement	Compression	Base	Head	Delta
Web	JavaScript bundle	Uncompressed	35.8 KiB	35.8 KiB	0 B
Web	JavaScript bundle	gzip	11.2 KiB	11.2 KiB	-1 B
Web	npm package (.tgz)	gzip	100.0 KiB	100.0 KiB	-61 B

Web package files (uncompressed)

These are uncompressed file sizes; they do not sum to the compressed package size above.

File	Base	Head	Delta
dist/chunks/shopify-checkout.js.map	266.2 KiB	266.2 KiB	+5 B
dist/custom-elements.json	54.7 KiB	54.7 KiB	0 B
dist/index.d.ts	49.5 KiB	49.5 KiB	0 B
dist/chunks/shopify-checkout.js	35.4 KiB	35.4 KiB	0 B
README.md	25.1 KiB	25.0 KiB	-153 B
package.json	4.1 KiB	4.1 KiB	0 B
LICENSE	1.1 KiB	1.1 KiB	0 B
dist/shopify-checkout.js.map	850 B	850 B	0 B
dist/index.js	255 B	255 B	0 B
dist/shopify-checkout.js	156 B	156 B	0 B
dist/shopify-checkout.d.ts	33 B	33 B	0 B

How sizes are measured

Measured from the PR base SHA and PR head SHA. Web bundle rows sum shipped .js, .mjs, and .cjs files under dist/, excluding source maps and declarations. The gzip bundle size sums files compressed individually with gzip -n -9. npm package sizes are gzip-compressed .tgz archives; Android AAR sizes are ZIP archives. Package sizes are not final app binary sizes.

[westeezy]

LGTM i dont think we need bubble behavior so this is excellent