Grid/contacts unification step 1: real contact_id link + grid as front door (v0.1.0:52)

Structural fix for the duplicate-people class of bug: instead of matching a grid
contact "pill" to a contacts row heuristically by name/email (which drifted and
caused the 1406 double-count), link them by id.

Backend:
- Migration 0004: fundraising_contacts.contact_id (additive, nullable, logical FK
  to contacts(id)) + index. Paired down migration.
- sync_fundraising_relational now stores the id that _upsert_contact_from_fundraising
  already returns, so every grid contact carries its contacts-table id.
- _backfill_grid_contact_ids: one-time, idempotent backfill on startup (re-runs the
  grid sync once if any row lacks contact_id), so existing data links immediately.
- entity_resolution: grid pass prefers the explicit contact_id link (match_kind
  'grid_link') over heuristic email / name+investor, guarded by a PRAGMA check so
  older DBs without the column still work.

Frontend:
- Fundraising grid "+ Row" -> "+ Investor" (clear, single investor entry point).
- Contacts page: the "+ Add Contact" trigger is replaced by a pointer to the grid;
  the page is now a read/search/edit view (ContactDetailPanel still edits all
  fields). New people are added from the grid. No contact data is removed.

Tests: backend/ingest/test_entity_resolution.py extended (explicit-link case, 11/11)
and a new backend/test_grid_contact_link.py integration test (init_db applies 0004,
sync populates contact_id to the right contact, re-sync is idempotent). py_compile +
frontend html.parser clean.

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

backend/server.py

@@ -462,6 +462,13 @@ def init_db():
     except Exception as _e:
         print(f"[migrations] core migration warning: {_e}")
 
+    # One-time: populate the new fundraising_contacts.contact_id (migration 0004)
+    # by re-running the grid→relational sync. No-op once every row is linked.
+    try:
+        _backfill_grid_contact_ids(conn)
+    except Exception as _e:
+        print(f"[backfill] grid contact_id backfill warning: {_e}")
+
     conn.close()
     print(f"Database initialized at {DB_PATH}")
 
@@ -977,6 +984,32 @@ def _sync_contact_to_fundraising_state(conn, contact_row, actor_user_id=None, re
     """, (json.dumps(grid), json.dumps(next_views), next_version, actor_user_id, now()))
     sync_fundraising_relational(conn, grid, next_views, actor_user_id=actor_user_id)
 
+def _backfill_grid_contact_ids(conn):
+    """One-time backfill for migration 0004: populate fundraising_contacts.contact_id
+    by re-running the grid→relational sync once. Fires only when the column exists
+    AND some row still lacks a contact_id, so it runs once after the migration and is
+    a no-op thereafter. Safe + idempotent: the fundraising_* tables are derived and
+    rebuilt on every sync, and _upsert_contact_from_fundraising matches existing
+    contacts by email/name (never creates a duplicate on re-run)."""
+    try:
+        need = conn.execute("SELECT 1 FROM fundraising_contacts WHERE contact_id IS NULL LIMIT 1").fetchone()
+    except sqlite3.OperationalError:
+        return  # contact_id column not present (migration 0004 not applied)
+    if not need:
+        return
+    row = conn.execute("SELECT grid_json, views_json FROM fundraising_state WHERE id = 'main'").fetchone()
+    if not row or not row[0]:
+        return
+    try:
+        grid = json.loads(row[0])
+        views = json.loads(row[1]) if row[1] else []
+    except Exception:
+        return
+    sync_fundraising_relational(conn, sanitize_fundraising_grid(grid), views)
+    conn.commit()
+    print("[backfill] populated fundraising_contacts.contact_id from grid sync")
+
+
 def sync_fundraising_relational(conn, grid, views, actor_user_id=None):
     columns = grid.get('columns', []) if isinstance(grid, dict) else []
     rows = grid.get('rows', []) if isinstance(grid, dict) else []
@@ -1084,23 +1117,23 @@ def sync_fundraising_relational(conn, grid, views, actor_user_id=None):
                 contact_payload = dict(c)
                 if lead_source and not str(contact_payload.get('source') or '').strip():
                     contact_payload['source'] = lead_source
-                _upsert_contact_from_fundraising(conn, investor_name, contact_payload, actor_user_id=actor_user_id)
+                linked_contact_id = _upsert_contact_from_fundraising(conn, investor_name, contact_payload, actor_user_id=actor_user_id)
                 conn.execute("""
                     INSERT INTO fundraising_contacts (
-                        id, investor_id, full_name, email, title, city, state, country, location_query, sort_order, updated_at
-                    ) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
+                        id, investor_id, full_name, email, title, city, state, country, location_query, sort_order, contact_id, updated_at
+                    ) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
                 """, (
                     generate_id(), investor_id, full_name, email, str(c.get('title') or ''),
                     str(c.get('city') or ''), str(c.get('state') or ''), str(c.get('country') or ''),
-                    str(c.get('location_query') or ''), i, now()
+                    str(c.get('location_query') or ''), i, linked_contact_id, now()
                 ))
         elif isinstance(contacts, str) and contacts.strip():
-            _upsert_contact_from_fundraising(conn, investor_name, {"name": contacts.strip(), "email": "", "title": "", "source": lead_source}, actor_user_id=actor_user_id)
+            linked_contact_id = _upsert_contact_from_fundraising(conn, investor_name, {"name": contacts.strip(), "email": "", "title": "", "source": lead_source}, actor_user_id=actor_user_id)
             conn.execute("""
                 INSERT INTO fundraising_contacts (
-                    id, investor_id, full_name, email, title, city, state, country, location_query, sort_order, updated_at
-                ) VALUES (?, ?, ?, '', '', '', '', '', '', 0, ?)
-            """, (generate_id(), investor_id, contacts.strip(), now()))
+                    id, investor_id, full_name, email, title, city, state, country, location_query, sort_order, contact_id, updated_at
+                ) VALUES (?, ?, ?, '', '', '', '', '', '', 0, ?, ?)
+            """, (generate_id(), investor_id, contacts.strip(), linked_contact_id, now()))
 
         conn.execute("DELETE FROM fundraising_commitments WHERE investor_id = ?", (investor_id,))
         for _, col in fund_columns: