BTC dominance just hit 60%. This is the level that has historically either launched altseason or killed it — and right now, the data is leaning one way. Here's your 4-step playbook. Step 1: Watch the dominance curve. If it starts rolling over from this 60% level, capital is about to rotate hard into altcoins. That's your green light. Step 2: Check the ETH/BTC pair. When Ethereum starts outperformi…