feat: add examples and enhance MEV protection services

This commit adds comprehensive examples for various trading operations including:
- PumpFun copy and sniper trading
- Bonk copy and sniper trading
- PumpSwap trading
- Raydium CPMM and AMM V4 trading
- Middleware system demonstration
- Event subscription

Enhanced MEV protection services with FlashBlock and Node1 integration.
Updated instruction modules for bonk, pumpswap, and raydium_cpmm.
Improved SWQOS modules for better transaction handling.

examples/middleware_system/Cargo.toml

@@ -0,0 +1,10 @@
+[package]
+name = "middleware_system"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+sol-trade-sdk = { path = "../.." }
+solana-sdk = "2.3.0"
+tokio = { version = "1", features = ["full"] }
+anyhow = "1.0.79"

examples/middleware_system/src/main.rs

@@ -0,0 +1,110 @@
+use anyhow::Result;
+use sol_trade_sdk::{
+    common::{AnyResult, PriorityFee, TradeConfig},
+    swqos::{SwqosConfig, SwqosRegion},
+    trading::{
+        core::params::PumpSwapParams, factory::DexType, middleware::builtin::LoggingMiddleware,
+        InstructionMiddleware, MiddlewareManager,
+    },
+    SolanaTrade,
+};
+use solana_sdk::{
+    commitment_config::CommitmentConfig, instruction::Instruction, pubkey::Pubkey,
+    signature::Keypair,
+};
+use std::{str::FromStr, sync::Arc};
+
+#[tokio::main]
+async fn main() -> Result<(), Box<dyn std::error::Error>> {
+    test_middleware().await?;
+    Ok(())
+}
+
+/// Custom middleware
+#[derive(Clone)]
+pub struct CustomMiddleware;
+
+impl InstructionMiddleware for CustomMiddleware {
+    fn name(&self) -> &'static str {
+        "CustomMiddleware"
+    }
+
+    fn process_protocol_instructions(
+        &self,
+        protocol_instructions: Vec<Instruction>,
+        protocol_name: String,
+        is_buy: bool,
+    ) -> Result<Vec<Instruction>> {
+        // do anything you want here
+        // you can modify the instructions here
+        Ok(protocol_instructions)
+    }
+
+    fn process_full_instructions(
+        &self,
+        full_instructions: Vec<Instruction>,
+        protocol_name: String,
+        is_buy: bool,
+    ) -> Result<Vec<Instruction>> {
+        // do anything you want here
+        // you can modify the instructions here
+        Ok(full_instructions)
+    }
+
+    fn clone_box(&self) -> Box<dyn InstructionMiddleware> {
+        Box::new(self.clone())
+    }
+}
+
+/// Create SolanaTrade client
+/// Initializes a new SolanaTrade client with configuration
+async fn create_solana_trade_client() -> AnyResult<SolanaTrade> {
+    println!("Creating SolanaTrade client...");
+
+    // In real transactions, use your own private key to initialize the payer
+    let payer = Keypair::new();
+    let rpc_url = "https://api.mainnet-beta.solana.com".to_string();
+
+    let swqos_configs = vec![SwqosConfig::Default(rpc_url.clone())];
+
+    let trade_config = TradeConfig {
+        rpc_url,
+        commitment: CommitmentConfig::confirmed(),
+        priority_fee: PriorityFee::default(),
+        swqos_configs,
+        lookup_table_key: None,
+    };
+
+    let solana_trade_client = SolanaTrade::new(Arc::new(payer), trade_config).await;
+    println!("SolanaTrade client created successfully!");
+
+    Ok(solana_trade_client)
+}
+
+async fn test_middleware() -> AnyResult<()> {
+    let mut client = create_solana_trade_client().await?;
+    // SDK example middleware that prints instruction information
+    // You can reference LoggingMiddleware to implement the InstructionMiddleware trait for your own middleware
+    let middleware_manager = MiddlewareManager::new().add_middleware(Box::new(CustomMiddleware));
+    client = client.with_middleware_manager(middleware_manager);
+    let mint_pubkey = Pubkey::from_str("pumpCmXqMfrsAkQ5r49WcJnRayYRqmXz6ae8H7H9Dfn")?;
+    let buy_sol_cost = 100_000;
+    let slippage_basis_points = Some(100);
+    let recent_blockhash = client.rpc.get_latest_blockhash().await?;
+    let pool_address = Pubkey::from_str("539m4mVWt6iduB6W8rDGPMarzNCMesuqY5eUTiiYHAgR")?;
+    client
+        .buy(
+            DexType::PumpSwap,
+            mint_pubkey,
+            buy_sol_cost,
+            slippage_basis_points,
+            recent_blockhash,
+            None,
+            Box::new(PumpSwapParams::from_pool_address_by_rpc(&client.rpc, &pool_address).await?),
+            None,
+            true,
+        )
+        .await?;
+    println!("tip: This transaction will not succeed because we're using a test account. You can modify the code to initialize the payer with your own private key");
+    Ok(())
+}