perf: P0/P1/P2 low-latency and maintainability improvements

P0:
- blockhash/nonce: get_transaction_blockhash returns Result; buy/sell entry validation
- Bonk sell: remove RPC get_token_balance from build path; require caller to pass input_amount
- Hot path: drop redundant dex_type/protocol_params clone; tip via sol_f64_to_lamports (no String)
- compute_budget cache uses Arc; extend_compute_budget_instructions avoids SmallVec clone

P1:
- middleware protocol_name takes &str; executor destructures result once to avoid signatures/submit_timings clone
- Error messages include dex context; params use Copy for Pubkey; pumpswap utils clone only Pool for pools[0]

P2:
- transaction_pool capacity constants; TIP_ACCOUNT_CACHE marked allow(dead_code)
- Fix error copy in raydium_amm_v4 / meteora_damm_v2 to correct protocol names

Made-with: Cursor

src/instruction/utils/pumpswap.rs

@@ -353,8 +353,8 @@ pub async fn find_by_base_mint(
     }
 
     pools.sort_by(|a, b| b.1.lp_supply.cmp(&a.1.lp_supply));
-    let (address, pool) = pools[0].clone();
-    Ok((address, pool))
+    let first = &pools[0];
+    Ok((first.0, first.1.clone()))
 }
 
 pub async fn find_by_quote_mint(
@@ -405,8 +405,8 @@ pub async fn find_by_quote_mint(
     }
 
     pools.sort_by(|a, b| b.1.lp_supply.cmp(&a.1.lp_supply));
-    let (address, pool) = pools[0].clone();
-    Ok((address, pool))
+    let first = &pools[0];
+    Ok((first.0, first.1.clone()))
 }
 
 /// 按 mint 查找 PumpSwap 池（本函数仅用于 PumpSwap，其他 DEX 勿用）。