Render server-native scientific branch results

[vaalessi]

What changed

• Add an explicit ?mode=scientific path that posts the IRAK4/RA labrador.run-setup.v3 replay frame with presentationMode: SCIENTIFIC and one HypGen run per selected focus.
• Add read-only ?run=<LR-id> attachment without creating another run.
• Consume labrador.scientific-snapshot.v1 branch/node artifacts while preserving the legacy snapshot contract.
• Show real biomarker and mechanistic/PD focus branches, native simulated_* fields, producer identity, refs, hashes, origins, and exact terminal failures.
• Invoke and render server Highlander results, including frontier/dominated/incomparable membership and the producer-grounded next evidence action.
• Keep scientific membership independent of browser display metrics and representative values.
• Show a watermark only for an explicit REPRESENTATIVE_DEMO snapshot.

Demo boundary

The default URL and legacy v0 behavior remain unchanged. Scientific replay and attach modes are explicit query-string opt-ins. This branch does not deploy or update the working demo.

Verification

• node --test tests/*.test.mjs — 25/25 passing
• node verify_functional_app.mjs — passing
• node verify_mockup.mjs — passing
• node --check app/js/app.js — passing
• git diff --check — passing
• Browser launch flow: fixture API accepted the exact scientific v3 POST, rendered three focus branches and the server Highlander result, with no console warnings/errors.
• Browser attach flow: ?mode=scientific&run=LR-SCIENTIFIC-TEST loaded the existing run without another create call.
• Default browser flow still presents the legacy local-orchestrated v0 setup.

Integration note

This is intentionally a draft until the compatible orchestrator scientific snapshot and Highlander endpoint branches are pinned and tested together.