CSV/JSON export of current registry state #138

CSV/JSON export of current registry state

Problem

Researchers/analysts who want the current scored-protocol data have to hit the API directly and parse JSON themselves. There's no one-shot downloadable export of what the registry currently shows.

Proposed fix

• A snapshot export, not historical — one row per currently-scored protocol, at its latest run's state: score, category, per-factor breakdown, methodology_version, operationalState

• Support both CSV and JSON output (e.g. ?format=csv / ?format=json on one endpoint, or two clearly-named endpoints)

• This mirrors exactly what the registry page currently displays — no additional historical data, no aggregation beyond "current state, exported"
  Where to look

• Same underlying query the registry page//v1/protocols already uses for its ranked listing — this is a formatting/export layer on top of existing data, not a new data source

• CSV generation likely needs a small library or hand-rolled formatter; check what's already a dependency before adding one
  Suggested first steps

1. Confirm the export uses the exact same underlying data/query as /v1/protocols (don't let scope creep into recomputing anything)
2. Implement JSON export first (trivial — it's close to the existing API shape), then CSV formatting on top
3. Decide filename/response headers for triggering a browser download vs. just returning raw text
4. Document both formats in API.md
   Not in scope

• Historical export (multiple runs per protocol) — that's a separate concern
• Filtering/customizing which fields export — ship the full current shape first, add filtering later if requested