feat(reachability): G1 cold-start lifeline fallback reply (no silent … #3866

Job	Run time
Standards Enforcement Coverage	13s
Docs Coverage	16s
Cartographer Freshness	15s
Type Check	1m 0s
Repo Invariants	12s
Unit Tests (node 20, shard 4/4)	8m 2s
Unit Tests (node 20, shard 3/4)	5m 50s
Unit Tests (node 20, shard 2/4)	6m 8s
Unit Tests (node 22, shard 1/4)	8m 30s
Unit Tests (node 22, shard 2/4)	6m 37s
Unit Tests (node 22, shard 3/4)	6m 2s
Unit Tests (node 20, shard 1/4)	8m 20s
Unit Tests (node 22, shard 4/4)	7m 42s
E2E Tests	3m 1s
Integration Tests	4m 11s
Build	50s
Contract Tests (Live API)	23s
	1h 7m 32s

Provide feedback