Add NatSpec to recenter() documenting that the function always reverts
on failure (never silently returns false), listing all four revert
conditions, and clarifying that both true/false return values represent
a successfully-executed recenter with the value indicating price
direction (up vs down relative to previous anchor centre).
Also fix StrategyExecutor.maybeRecenter() to capture the isUp return
value from lm.recenter() and include it in the log output, making
price direction visible in backtesting replays.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>