Tokens the Fleet Carries

The first number in any fleet plan is monthly owned capacity, and it is owned tokens equal to cards times tokens/sec per card times the seconds in a month. A month is 730 hours, or 2,628,000 seconds. The numbers interviewers check: 700 H100s carrying an 8B chat at the batched steady state (10,000 aggregate tokens/sec per card) carry 18.396 terabytes of tokens a month; 9,800 B200s on a 70B premium (1,680 tokens/sec) carry 43.267T - and against a 10T demand curve that same fleet is 71% idle, which is where the balance sheet lesson lives. Everything downstream (the carry, the idle fraction, the blend) starts from this line. Implement owned_tokens_tb(fleet, tok_s): return the monthly owned capacity in terabytes of tokens, rounded to 3 decimals.