Explore source-fragment conversion for targeted site updates

[chubes4]

Problem

The SSI Studio experiment needs a safe update path between full re-import and hand-editing complex block trees.

For requests like "redesign the hero" or "add a new pricing section", the ideal workflow may be:

agent generates a static HTML/CSS fragment
  -> BFB converts just that fragment to blocks
  -> Studio/SSI replaces only the matching WordPress region
  -> rest of the page remains untouched

BFB may need a clearer fragment-conversion contract for targeted updates.

Related SSI issue: chubes4/static-site-importer#110

Proposed direction

Explore support for source-fragment conversion that preserves enough diagnostics/provenance for targeted replacement.

Potential needs:

• convert a standalone HTML fragment with scoped CSS/classes,
• return editor-valid block markup plus diagnostics,
• preserve source selector or region identifier in conversion metadata,
• report fallbacks/content loss at fragment scope,
• avoid requiring full-page imports for localized redesigns.

Acceptance criteria for an experiment

• A static hero/section fragment can be converted to valid blocks without a full-page import.
• Conversion diagnostics are scoped to the fragment.
• Existing full-document conversion behavior remains unchanged.
• SSI/Studio can use the output for selective region replacement in a future update workflow.

Links

• SSI provenance issue: Persist import provenance and support selective re-import decisions static-site-importer#110
• Studio SSI draft PR: Experiment: use Static Site Importer for generated local sites Automattic/studio#3309
• Block Format Bridge: https://github.com/chubes4/block-format-bridge

AI assistance

• AI assistance: Yes
• Tool(s): OpenCode (gpt-5.5)
• Used for: Drafting the BFB fragment-conversion issue from architecture discussion; Chris remains responsible for review and prioritization.