fix(crud): skip generated and read-only columns on insert and update

Read-merge-update wrote every model column back, so GENERATED ALWAYS
columns failed with SQLSTATE 428C9. Add a bun 'generated' tag option,
reflection.NonWritableColumns/RemoveNonWritableColumns, and apply them
in resolvespec, restheadspec, websocketspec, mqttspec, resolvemcp and
the nested CUD processor. Add ExcludeColumn to InsertQuery/UpdateQuery
for model-based writes.

pkg/common/adapters/database/gorm.go

@@ -751,6 +751,13 @@ func (g *GormInsertQuery) OnConflict(action string) common.InsertQuery {
 	return g
 }
 
+func (g *GormInsertQuery) ExcludeColumn(columns ...string) common.InsertQuery {
+	if len(columns) > 0 {
+		g.db = g.db.Omit(columns...)
+	}
+	return g
+}
+
 func (g *GormInsertQuery) Returning(columns ...string) common.InsertQuery {
 	g.returningColumns = columns
 	return g
@@ -930,6 +937,13 @@ func (g *GormUpdateQuery) SetMap(values map[string]interface{}) common.UpdateQue
 	return g
 }
 
+func (g *GormUpdateQuery) ExcludeColumn(columns ...string) common.UpdateQuery {
+	if len(columns) > 0 {
+		g.db = g.db.Omit(columns...)
+	}
+	return g
+}
+
 func (g *GormUpdateQuery) Where(query string, args ...interface{}) common.UpdateQuery {
 	g.db = g.db.Where(query, args...)
 	return g