feat: v0.5.5 - enhanced priority fee system and dependency updates

- Update solana-streamer-sdk to 0.4.1
- Refactor priority fee API (custom_buy_tip_fee → custom_priority_fee)
- Simplify documentation and clean up examples

BREAKING CHANGE: priority fee parameter type changed

examples/pumpfun_sniper_trading/src/main.rs

@@ -114,7 +114,6 @@ async fn pumpfun_sniper_trade_with_shreds(trade_info: PumpFunTradeEvent) -> AnyR
             Box::new(PumpFunParams::from_dev_trade(&trade_info, None)),
             None,
             true,
-            None,
         )
         .await?;
 
@@ -141,7 +140,6 @@ async fn pumpfun_sniper_trade_with_shreds(trade_info: PumpFunTradeEvent) -> AnyR
             Box::new(PumpFunParams::immediate_sell(trade_info.creator_vault, true)),
             None,
             true,
-            None,
         )
         .await?;