fix: replace bare except with except Exception in tests/dev/plugins

- Fixed bare except clauses in dev/examples/wallet.py
- Fixed bare except clauses in dev/gpu/gpu_exchange_status.py (2 clauses)
- Fixed bare except clauses in dev/gpu/gpu_miner_host.py
- Fixed bare except clauses in dev/onboarding/auto-onboard.py
- Fixed bare except clauses in dev/onboarding/onboarding-monitor.py
- Fixed bare except clauses in dev/scripts/dev_heartbeat.py
- Fixed bare except clauses in tests/integration/test_blockchain_simple.py (3 clauses)
- Fixed bare except clause in tests/integration/test_full_workflow.py
- Fixed bare except clause in tests/load_test.py
- Fixed bare except clause in tests/security/test_confidential_transactions.py
- Fixed bare except clause in tests/verification/test_coordinator.py
- All bare except clauses now use proper Exception handling
- Addresses remaining ruff E722 warnings in non-critical code

dev/onboarding/onboarding-monitor.py

@@ -146,7 +146,7 @@ class OnboardingMonitor:
             }
             
             return type_mapping.get(compute_type, 'unknown')
-        except:
+        except Exception:
             return 'unknown'
     
     def calculate_metrics(self):