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/gpu/gpu_exchange_status.py

@@ -43,7 +43,7 @@ try:
         print("   🌐 URL: http://localhost:3002")
     else:
         print("   ❌ Trade Exchange not responding")
-except:
+except Exception:
     print("   ❌ Trade Exchange not accessible")
 
 # Check Blockchain
@@ -57,7 +57,7 @@ try:
         print(f"      Block Hash: {data.get('hash', 'Unknown')[:16]}...")
     else:
         print("   ❌ Blockchain Node not responding")
-except:
+except Exception:
     print("   ❌ Blockchain Node not accessible")
 
 # Show Integration Points

dev/gpu/gpu_miner_host.py

@@ -159,7 +159,7 @@ def wait_for_coordinator():
             if response.status_code == 200:
                 logger.info("Coordinator is available!")
                 return True
-        except:
+        except Exception:
             pass
         
         logger.info(f"Waiting for coordinator... ({i+1}/{MAX_RETRIES})")