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/trading/middleware/builtin.rs

@@ -14,7 +14,7 @@ impl InstructionMiddleware for LoggingMiddleware {
     fn process_protocol_instructions(
         &self,
         protocol_instructions: Vec<Instruction>,
-        protocol_name: String,
+        protocol_name: &str,
         is_buy: bool,
     ) -> Result<Vec<Instruction>> {
         println!("-------------------[{}]-------------------", self.name());
@@ -32,7 +32,7 @@ impl InstructionMiddleware for LoggingMiddleware {
     fn process_full_instructions(
         &self,
         full_instructions: Vec<Instruction>,
-        protocol_name: String,
+        protocol_name: &str,
         is_buy: bool,
     ) -> Result<Vec<Instruction>> {
         println!("-------------------[{}]-------------------", self.name());