Phase 1: investor↔contacts (member_of), system status, thesis seed v1

- entity_resolution: emit member_of relationship edges (contact -> investor),
  so one investor entity owns many contacts (institution) and a HNWI is the N=1
  case; crm_tools.get_investor_contacts + get_entity contacts/member_of; MCP tool.
- seed_synthetic: multi-contact institutions to exercise it (Harbor & Vine = 5).
- server.py: GET /api/system/status (index/entity/thesis/activity health) for an
  in-app status view (no shell needed to verify the index).
- docs/thesis-seed-v1.md: grounded v1 thesis (throughline, 6 pillars, objections,
  per-segment angles, voice) drawn from Ten31's newsletter/site/essays.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/mcp/server.py

@@ -47,6 +47,13 @@ def get_interaction_history(lp_id: str, limit: int = 20) -> dict:
     return t.get_interaction_history(lp_id, limit=limit)
 
 
+@mcp.tool()
+def get_investor_contacts(lp_id: str) -> dict:
+    """List all contacts (people) belonging to an investor entity — the
+    one-investor-to-many-contacts relationship (e.g. a family office's several people)."""
+    return t.get_investor_contacts(lp_id)
+
+
 # ── retrieval modes ──
 @mcp.tool()
 def hybrid_search(query: str, top_k: int = 8, lp_id: str = "", doc_type: str = "",