MeteredClient wraps a ChatClient, sums the provider's usage rows per call,
prices them from a Model manifest's parameters (cache-hit, input, output per
million), and raises BudgetExhausted before a call once the usd or calls
ceiling is reached. A 401/402 or "Insufficient Balance" failure becomes
AccountError with the provider's message. An unpriced model reports usd None,
never zero, and refuses a usd budget; summary() gives the spend block of a
task's summary.json.
The two plane modules are registered as spec-owned in the module audit (their
consumers land in tasks 3-4) and the audit manifest is regenerated.
Co-Authored-By: Claude Fable 5.1 <[email protected]>
Claude-Session: https://claude.ai/code/session_01EmM1j46qgKMh3zqD1QMwEo
