- Add KellyCalculator (Domain/Betting): pure fractional-Kelly stake from win
probability, decimal odds, bankroll, and fraction (default quarter-Kelly).
Returns 0 on non-positive edge; truncates the suggestion down to 2 decimals
so it never exceeds the computed figure. 19 unit tests.
- MyBets: add a page-local stake helper (bankroll + win-probability inputs) that
suggests a quarter-Kelly stake from the form's rate, with an Apply button and a
no-edge message. Win probability is user-supplied, not derived from a signal.
- Localization (en+ru) for the Kelly helper and the export-hub keys (shared resx).
