Fixed false burn-rate warnings triggering right after startup
Previously, because there weren't enough samples to reliably project depletion times, the app would startlingly throw red warnings right after starting up, even when you'd barely used 1% or 14% of your quota. We've now added two safety valves: first, the system must collect enough samples over a sufficient period (at least 5 samples spanning 5 minutes) before it begins estimating; second, the warning only actually displays when you've consumed at least 50% of your quota. Otherwise, it simply keeps the standard "Resets in X" text. It's like sprinting for the very first minute of a run — your coach won't instantly warn you of exhaustion, but will wait until you've settled into a pace and actually drained half your stamina before giving a reliable heads-up.