feat(placeholder): expand custom placeholders and integrate MiniPlaceholders

[Chiloven945]

…holders

• centralize placeholder processing into a single pipeline (remove scattered handling)
• add parameterized unit placeholders: {days: suffix} {hours: suffix} {minutes: suffix} {seconds: suffix}
  • hide token when value is 0 if suffix is provided
• add formatted remaining placeholder: {remaining:} (e.g. {remaining:hh:mm:ss}, {remaining:d天 hh:mm:ss})
  • suppress zero-valued units when a unit suffix is present
• enable {animation:} frames to pass through the same placeholder + MiniMessage pipeline
• integrate MiniPlaceholders as an optional dependency via TagResolver (no reflection)
  • render per-player where applicable (bossbar/title) for audience-aware placeholders
• update config comments and wiki/docs to describe new placeholder formats

BREAKING CHANGE: placeholder rendering has been refactored into a unified pipeline; any custom code that depended on old scattered render paths must be updated.