Member Research framework design (#186)

[jonschull]

Summary

Phase 1 design document for the Member Research framework (Issue #186).

• BigMap Legacy is already done (PR feat: Convert 4,073 legacy BigMap entries to BigMap2 format #188). This PR scopes to Member Research only.
• Answers Jon's 5 open questions from the Feb 12 comment: delta detection, trigger mechanism, output integration, API costs, quality control.
• Revised architecture from the original Phase 1 comment: flat structure, clear API vs Interactive mode distinction, staged review flow.

Key Design Decisions

• Staged output: AI-researched projects go to era_projects_staging.csv (not direct to live CSV). Jon reviews before promoting to era_projects_export.csv.
• Delta detection: era_projects_state.json tracks {participant_id: last_researched_at + profile_hash}. Reruns only process new/changed members by default.
• Mode B (Interactive): Claude Code IS the pipeline — not Python calling Claude Code tools. Python manages state; Claude does the research. Free on Max subscription.
• Mode A (API): SerpAPI + Anthropic, ~$50 for all 906 members, deployable to Render.

Deliverables

Files Created For This Task

• era2/scripts/member_research/DESIGN.md - Full architecture document with decisions, prompts, error handling, and cost estimates

Stale Branch Warning

This branch was created from main. Cherry-pick only files listed above.

Validation

Design document is self-contained and doesn't touch any running systems.

Next Steps

Issue #186 is labeled needs-discussion. Jon should review the design, answer Q1–Q6 in DESIGN.md, and comment "Approved" to proceed to Phase 2 implementation.