sketch_cuckoo_delete_vs_bloom_bench.nx

sketch_cuckoo_delete_vs_bloom_bench.nx -- DELETE capability bench. CLAIM TO VALIDATE: Cuckoo filter (Fan-Andersen-Kaminsky-Mitzenmacher 2014) supports DELETE; Bloom filter (Bloom 1970) does NOT. Substrate ships both; this bench DEMONSTRATES the capability gap: items deleted from Cuckoo are correctly forgotten, while Bloom carries deleted items indefinitely. WORKLOAD: 1. Insert N=500 distinct keys into both. 2. Verify all 500 reported as present. 3. Delete first 100 keys from Cuckoo (Bloom has no delete op). 4. Query: Cuckoo no longer contains the deleted keys (with bounded false-positive noise from fingerprint collisions). Bloom STILL reports the deleted keys as present (cannot delete). MEASUREMENT: delete_forgotten_count_cuckoo: how many of the 100 deleted keys does Cuckoo correctly report as NOT-present? Expected: ~95-100 (5% FPR from fingerprint collisions is the Cuckoo theoretical bound). delete_forgotten_count_bloom: how many does Bloom report NOT-present? Expected: 0 (Bloom CANNOT forget). CAPABILITY EXCEED: Cuckoo forgets >=90% of deletes; Bloom forgets 0%.