refactor: optimize trading execution architecture and add wSOL management

- Simplify TradeExecutor interface by integrating middleware and swqos clients into params
- Refactor parallel execution module with dedicated buy/sell execute functions
- Add SOL wrapping/unwrapping functionality for wSOL management
- Remove redundant parameter passing in sell operations
- Delete example main.rs file
- Optimize transaction building with integrated parameter structures

BREAKING CHANGE: TradeExecutor interface simplified, middleware and swqos_clients now passed through params

src/trading/common/wsol_manager.rs

@@ -14,13 +14,13 @@ pub fn handle_wsol(payer: &Pubkey, amount_in: u64) -> SmallVec<[Instruction; 3]>
         );
 
     let mut insts = SmallVec::<[Instruction; 3]>::new();
+    insts.extend(create_associated_token_account_idempotent_fast(
+        &payer,
+        &payer,
+        &crate::constants::WSOL_TOKEN_ACCOUNT,
+        &crate::constants::TOKEN_PROGRAM,
+    ));
     insts.extend([
-        create_associated_token_account_idempotent_fast(
-            &payer,
-            &payer,
-            &crate::constants::WSOL_TOKEN_ACCOUNT,
-            &crate::constants::TOKEN_PROGRAM,
-        ),
         transfer(&payer, &wsol_token_account, amount_in),
         spl_token::instruction::sync_native(&crate::constants::TOKEN_PROGRAM, &wsol_token_account)
             .unwrap(),
@@ -29,33 +29,33 @@ pub fn handle_wsol(payer: &Pubkey, amount_in: u64) -> SmallVec<[Instruction; 3]>
     insts
 }
 
-pub fn close_wsol(payer: &Pubkey) -> Instruction {
+pub fn close_wsol(payer: &Pubkey) -> Vec<Instruction> {
     let wsol_token_account =
         crate::common::fast_fn::get_associated_token_address_with_program_id_fast(
             &payer,
             &crate::constants::WSOL_TOKEN_ACCOUNT,
             &crate::constants::TOKEN_PROGRAM,
         );
-    crate::common::fast_fn::get_cached_instruction(
+    crate::common::fast_fn::get_cached_instructions(
         crate::common::fast_fn::InstructionCacheKey::CloseWsolAccount {
             payer: *payer,
             wsol_token_account,
         },
         || {
-            close_account(
+            vec![close_account(
                 &crate::constants::TOKEN_PROGRAM,
                 &wsol_token_account,
                 &payer,
                 &payer,
                 &[],
             )
-            .unwrap()
+            .unwrap()]
         },
     )
 }
 
 #[inline]
-pub fn create_wsol_ata(payer: &Pubkey) -> Instruction {
+pub fn create_wsol_ata(payer: &Pubkey) -> Vec<Instruction> {
     create_associated_token_account_idempotent_fast(
         &payer,
         &payer,