feat: major gas fee strategy and documentation overhaul

- feat(gas): add comprehensive gas fee strategy management system
  * Implement GasFeeStrategyType with Default/LowTipHighCuPrice/HighTipLowCuPrice strategies
  * Add dynamic gas fee configuration per SWQOS service and trade type
  * Integrate arc-swap for thread-safe strategy updates

- docs: restructure documentation with dedicated guides
  * Add ADDRESS_LOOKUP_TABLE.md/CN.md for lookup table configuration
  * Add NONCE_CACHE.md/CN.md for nonce management documentation
  * Add TRADING_PARAMETERS.md/CN.md for comprehensive parameter guides
  * Simplify main README.md with focused overview

- refactor: update all examples with new gas fee strategy integration
  * Modernize 14 trading examples with consistent parameter handling
  * Improve error handling and configuration management
  * Enhance parallel trading implementation

docs/NONCE_CACHE.md

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+# Nonce Cache Guide
+
+This guide explains how to use Nonce Cache in Sol Trade SDK to implement transaction replay protection and optimize transaction processing.
+
+## 📋 What is Nonce Cache?
+
+Nonce Cache is a global singleton cache system for managing durable nonce accounts in the Solana network. Durable nonce is a Solana feature that allows you to create transactions that remain valid for extended periods, not limited by the 150-block constraint of recent block hashes.
+
+## 🚀 Core Benefits
+
+- **Transaction Replay Protection**: Prevents the same transaction from being executed multiple times
+- **Extended Time Window**: Transactions can remain valid for longer periods
+- **Network Performance Optimization**: Reduces dependency on recent block hashes
+- **Transaction Determinism**: Provides consistent transaction processing experience
+- **Offline Transaction Support**: Supports offline processing of pre-signed transactions
+
+## 🛠️ Implementation
+
+### Prerequisites:
+
+You need to create a nonce account for your payer account first.
+Reference: https://solana.com/developers/guides/advanced/introduction-to-durable-nonces
+
+### 1. Initialize Nonce Cache
+
+First, set up the nonce account and initialize the cache:
+
+```rust
+use sol_trade_sdk::common::nonce_cache::NonceCache;
+
+// Set nonce account
+let nonce_account_str = "your_nonce_account_address_here";
+NonceCache::get_instance().init(Some(nonce_account_str.to_string()));
+```
+
+### 2. Fetch Nonce Information
+
+Get the latest nonce information from RPC:
+
+```rust
+// Fetch and update nonce information
+NonceCache::get_instance().fetch_nonce_info_use_rpc(&client.rpc).await?;
+
+// Get current nonce value
+let nonce_info = NonceCache::get_instance().get_nonce_info();
+let current_nonce = nonce_info.current_nonce;
+println!("Current nonce: {}", current_nonce);
+```
+
+### 3. Use Nonce in Transactions
+
+Pass the nonce as the recent_blockhash parameter to transactions:
+
+```rust
+let buy_params = sol_trade_sdk::TradeBuyParams {
+    dex_type: DexType::PumpFun,
+    mint: mint_pubkey,
+    sol_amount: buy_sol_amount,
+    slippage_basis_points: Some(100),
+    recent_blockhash: current_nonce, // Use nonce as blockhash
+    extension_params: Box::new(PumpFunParams::from_trade(&trade_info, None)),
+    lookup_table_key: None,
+    wait_transaction_confirmed: true,
+    create_wsol_ata: false,
+    close_wsol_ata: false,
+    create_mint_ata: true,
+    open_seed_optimize: false,
+};
+
+// Execute transaction
+client.buy(buy_params).await?;
+```
+
+## 🔄 Nonce Lifecycle
+
+1. **Initialize**: Set nonce account address
+2. **Fetch**: Get the latest nonce value from RPC
+4. **Use**: Use as blockhash in transactions
+6. **Refresh**: Re-fetch new nonce value before next use
+
+## 🔗 Related Documentation
+
+- [Example: Nonce Cache](../examples/nonce_cache/)