Add first-class service worker builds

[bcomnes]

Summary

• detect one site-level service-worker.{js,mjs,cjs,ts,mts,cts} source anywhere under src and report duplicate service-worker sources clearly
• build the service worker through esbuild to stable /service-worker.js while keeping normal hashed outputs elsewhere
• add service-worker to the output manifest kind schema and docs
• update watch mode and fixtures so service worker changes rebundle without page rebuilds

Tests

• npm run test:tsc
• npm run test:neostandard
• npm run test:installed-check
• npm run test:node-test
• node --test lib/identify-pages.test.js test-cases/general-features/index.test.js test-cases/watch/index.test.js --test-reporter=spec

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[coveralls]

Coverage Report for CI Build 27571997321

Coverage decreased (-0.09%) to 92.784%

Details

• Coverage decreased (-0.09%) from the base build.
• Patch coverage: 2 uncovered changes across 1 file (168 of 170 lines covered, 98.82%).
• No coverage regressions found.

Uncovered Changes

File	Changed	Covered	%
index.js	13	11	84.62%
Total (5 files)	170	168	98.82%

Coverage Regressions

No coverage regressions found.

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Coverage Stats

Relevant Lines:	5164
Covered Lines:	4913
Line Coverage:	95.14%
Relevant Branches:	947
Covered Branches:	757
Branch Coverage:	79.94%
Branches in Coverage %:	Yes
Coverage Strength:	121.19 hits per line

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💛 - Coveralls