Fix code style: move import to top-level and use underscore prefix for unused variable

Co-authored-by: Steake <530040+Steake@users.noreply.github.com>

Author: Copilot

crates/bitcell-wallet/src/mnemonic.rs

@@ -5,6 +5,7 @@
 
 use crate::{Error, Result};
 use bip39::{Language, Mnemonic as Bip39Mnemonic};
+use rand::RngCore;
 use zeroize::Zeroize;
 
 /// Mnemonic word count options
@@ -43,7 +44,6 @@ impl Mnemonic {
         let mut entropy = vec![0u8; entropy_size];
 
         // Use rand to generate entropy
-        use rand::RngCore;
         rand::thread_rng().fill_bytes(&mut entropy);
 
         let mnemonic = Bip39Mnemonic::from_entropy(&entropy)

crates/bitcell-wallet/src/wallet.rs

@@ -156,12 +156,11 @@ impl Wallet {
 
             for (chain, lookahead) in chains {
                 for i in 0..lookahead {
-                    if let Err(e) = wallet.generate_address(chain, i) {
+                    if let Err(_e) = wallet.generate_address(chain, i) {
                         // Log warning but continue - address generation failure shouldn't
                         // prevent wallet creation
                         #[cfg(debug_assertions)]
-                        eprintln!("Warning: failed to generate address for chain {:?} at index {}: {}", chain, i, e);
-                        let _ = e; // Suppress unused warning in release
+                        eprintln!("Warning: failed to generate address for chain {:?} at index {}: {}", chain, i, _e);
                     }
                 }
             }