Oil posted its sixth straight weekly gain, the longest streak in more than a year, after OPEC+ heavyweights Saudi Arabia and Russia extended supply curbs into next month and US stockpiles sank by a record. West Texas Intermediate settled above $82 a barrel, taking gains during the six-week span to about 20%. Saudi Arabia said Thursday it would extend its unilateral 1 million barrel-a-day output cut into September and that the move could be prolonged further or even deepened. Russia will exten ....