Review fixes: narrow intake redact predicate to the bot's own nudge + edge tests

reviewer agent flagged the broadened redact_thread predicate (event_id OR in_reply==root)
as over-matching any plain reply to a thread root. Gate the bare-in_reply clause to the bot's
own sender (the nudge is always ours); thread children (cards/acks/human yes-no) still match by
rel_type=m.thread. Add unit edges for _name_similarity's all-generic fallback and a contact_id
NULL orphan case for the grid-blob email heal.

backend/test_intake_endpoints.py

@@ -103,6 +103,21 @@ def main():
     seed()
     token = server.create_token("u1", "grant", "admin")
 
+    # Unit: the distinctive-token similarity edges (the all-generic fallback path the endpoint
+    # seed can't naturally reach — no real investor is named purely with generic descriptors).
+    print("\n[unit: _name_similarity distinctive-token edges]")
+    sim = server._name_similarity
+    check(sim("Fortitude Investment Group", "Aether Investment Group") < 0.62,
+          f"generic-only overlap stays below threshold (got {sim('Fortitude Investment Group', 'Aether Investment Group'):.2f})")
+    check(sim("Aether Capital", "Aether Capital Partners") == 1.0,
+          f"distinctive 'aether' (generic descriptors stripped) scores 1.0 (got {sim('Aether Capital', 'Aether Capital Partners'):.2f})")
+    # Both sides all-generic → fallback compares full tokens on BOTH sides; shared generic word
+    # alone must not clear the bar.
+    check(sim("Capital Group", "Global Capital") < 0.62,
+          f"all-generic both sides stays below threshold (got {sim('Capital Group', 'Global Capital'):.2f})")
+    check(sim("Family Office", "Family Office") == 1.0,
+          "identical all-generic names still score 1.0 (early-out)")
+
     httpd = ThreadingHTTPServer(("127.0.0.1", 0), _Quiet)
     port = httpd.server_address[1]
     threading.Thread(target=httpd.serve_forever, daemon=True).start()