Hardcode human-resolved DCIDs; never resolve by search at runtime

Between 14 and 16 Sep, with no code change on our side, search_indicators returned 44 candidate variables for our fifteen topic queries and then 56 — nine topics gained, none lost, and every row present on both dates identical in every field. The graph did not move; retrieval over it did. Notably, "road traffic deaths" began returning undata/sdg/SH_STA_TRAF, the exact DCID our road-deaths pair uses, which it had not on the 14th.

Discovery through search stays the rule (REST is federated and will answer for other publishers). But once a human has resolved and graded a DCID it goes in crosswalk.json as a literal. A demo that resolves by search at showtime can change its answer while the data stands still.