Feat/website brand import

[herefindalex]

Summary

• Replace runtime Website Brand Capture with a request-bound Website Brand Import workflow.
• Let Admin generate a source-bound prompt, paste structured external-model output, review the proposed field-level diff, confirm content rights, and apply the result to the Website Working configuration.
• Add structured Organization, Header, Footer, Navigation, Theme, contact, and brand-layout handling with server-side normalization and validation.
• Update public rendering, responsive styles, accessibility contrast handling, Admin UI, localization copy, and embedded frontend assets.
• Remove the previous runtime browser-capture implementation and its tests.
• Keep broad engineering documentation changes in the separate docs/engineering-guides branch.

Scope and safety

• Import results are bound to the original request ID, source URL, prompt version, expiry, user, and current Working revision.
• Import applies only to Website Working state; it does not publish automatically.
• Rights confirmation is required before applying a validated proposal.
• The deployed Go process does not gain a browser, AI runtime, or external-model dependency.

Verification

• go test ./... — 396 tests passed
• go test -tags poc ./... -timeout=5m — 435 tests passed
• go vet ./... — passed
• pnpm --dir web/ui typecheck — passed
• pnpm --dir web/ui test — 50 tests passed
• Rebuilt embedded Admin and Public assets match the committed outputs

Before merge

• Require imported Headers to retain the core Search and RFQ actions.
• Make generated Product HTML render utility Search consistently with other public pages.
• Enforce the bundled JSON Schema during server-side validation.
• Expose unsupported-source observations and field evidence to Admin before apply.
• Correct the Brand Import preview condition and ensure preview represents the proposed configuration.

[thomas-chu-30]

approval

[thomas-chu-30]

Approval !!