Add static PWA manifest example

[bcomnes]

Summary

Adds a hand-rolled static PWA example that consumes the unstable Domstack manifest preview directly.

This PR is stacked on top of #262 / staic-client-cache and intentionally contains only the hand-rolled PWA example plus its root README/example script references.

Includes

• examples/pwa workspace
• Manifest filtering via domstack-manifest.settings.js
• First-class service-worker.js source built by Domstack
• Static route precaching and offline fallback behavior
• README documentation for running and testing the example

Validation

• npm --workspace @domstack/pwa-example run build
• npm run test:neostandard
• git --no-pager diff --check

[coveralls]

Coverage Report for CI Build 28766395572

Coverage increased (+0.06%) to 93.27%

Details

• Coverage increased (+0.06%) from the base build.
• Patch coverage: No coverable lines changed in this PR.
• No coverage regressions found.

Uncovered Changes

No uncovered changes found.

Coverage Regressions

No coverage regressions found.

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Coverage Stats

Relevant Lines:	5552
Covered Lines:	5288
Line Coverage:	95.24%
Relevant Branches:	1001
Covered Branches:	824
Branch Coverage:	82.32%
Branches in Coverage %:	Yes
Coverage Strength:	143.08 hits per line

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💛 - Coveralls