chore: bump version to 1.21.1

Release Notes:
- Remove redundant utils/qzmq (use ~/work/lux/qzmq instead)
- Restore factory.go for proper type exports
- Fix test/integration tests
- Remove incomplete AI integration code
- Package consolidation: core/, utils/, test/ organization
- All tests passing ✅

version/version.go

@@ -53,7 +53,7 @@ func Current() *Application {
 	return &Application{
 		Major: 1,
 		Minor: 21,
-		Patch: 0,
+		Patch: 1,
 		Name:  "lux",
 	}
 }

version/version_test.go

@@ -320,11 +320,11 @@ func TestCurrent(t *testing.T) {
 	require.NotNil(t, current)
 	require.Equal(t, 1, current.Major)
 	require.Equal(t, 21, current.Minor)
-	require.Equal(t, 0, current.Patch)
+	require.Equal(t, 1, current.Patch)
 	require.Equal(t, "lux", current.Name)
 
 	// Test string representation
-	require.Equal(t, "lux-1.21.0", current.String())
+	require.Equal(t, "lux-1.21.1", current.String())
 
 	// Test that calling Current multiple times returns consistent results
 	current2 := Current()