Add shared error codes with zh/en/ms messages, coded app exceptions,
and locale-aware global filter. Frontends send X-Locale so error text
matches the active UI language.
Co-authored-by: Cursor <cursoragent@cursor.com>
Admin: add match/player overview sub-nav; refine settlement flow and league
match management UI; improve action button enabled/disabled styles; enhance
logo upload and outright odds sync.
API: expose matchPhase/bettingOpen for closed matches; league publish guards;
settlement preview with auto score save; outright team auto-sync.
Player: watermark for closed/settled states; keep match and bet details visible;
remove default login credentials.
Co-authored-by: Cursor <cursoragent@cursor.com>