`total_return` from financials.rs:80-94 is the log-space cumulative growth
across every per-bar step_return: `exp(sum(ln(max(1+r, 1e-10)))) - 1`.
With ~4M per-bar step returns in a fold-convergence run, even sub-bps
positive bars compound to absurd magnitudes (observed: 1.93e37%) when
displayed as `{:+.2}%`. The math is correct; the display is broken.
Switching to `{:+.3e}%` shows the same magnitude compactly across the
full dynamic range without hiding the number. Comment added explaining
the underlying compute's HFT-inappropriate semantic so a future reader
knows the value is correct-but-meaningless rather than buggy.
Surfaced in T10 train-multi-seed-xkjkb seed-0 ep3 epoch summary while
the SP10 chain validates structural fixes. Cosmetic-only change; no
training-path impact.
368454788a