India’s solar sector has hit that awkward stage of adolescence where ambition seems to be outpacing demand. And now the adults in the room are issuing critical warnings. A new letter from the clean-energy ministry, quietly circulated to the finance ministry, urges lenders to think twice before showering cash on yet another wave of standalone module factories. When a government that spent the last three years cheerleading capacity expansion suddenly says “maybe don’t,” you can assume the oversupply problem is no longer a…