refactor: improve error handling and remove hardcoded credentials

- Changed bare except clauses to specific exception types in web3_utils.py, testing.py, messages.py, and message_storage.py
- Replaced print() calls with logger in testing.py, agent_discovery.py, compliance_agent.py, coordinator.py, trading_agent.py, keys.py, escrow.py, persistent_spending_tracker.py, sync_cli.py, and client.py
- Added logger initialization using get_logger(__name__) in compliance_agent.py, coordinator.py, trading_agent.py, keys.py, escrow.py, persistent_spending_tracker.py, and client.py
- Removed hardcoded secret

cli/examples/wallet.py

@@ -23,7 +23,7 @@ class AITBCWallet:
             try:
                 with open(self.wallet_file, 'r') as f:
                     return json.load(f)
-            except:
+            except (OSError, json.JSONDecodeError):
                 pass
         
         # Create new wallet