Rewrite fingerprinted srcset image references

[PrzemyslawKlys]

Summary

PowerForge now rewrites local image candidates in srcset and imagesrcset when asset hashing moves those files to fingerprinted names. It preserves descriptors, query strings, fragments, and inline data: URLs, including descriptorless candidates separated by commas.

This lets PowerForge websites content-hash mutable screenshots and responsive images without leaving references to files that no longer exist.

Validation

• 13 focused OptimizeDetailed tests pass
• a new regression contract covers source[srcset], img[srcset], preload imagesrcset, query/fragment suffixes, descriptorless candidates, and data: URLs
• CasaRay’s strict PowerForge website pipeline passes with 21 fingerprinted assets and a clean rendered-site audit

Review

An independent local review found a data: URL boundary issue. The fix was confirmed, and a directly caused descriptorless-candidate regression was then fixed and covered by the final focused test.