The OP announced a total budget of
$35 and I rolled my eyes. But hoodibaba! The headlight in post #5 combined the taillight in post #14 will only be about three or four bucks over that after shipping. The set is no Nabendynamo-driven Luxos U and Toplight Line, but it's bright enough to see by and been seen by any driver that's not drunk or texting. Color me impressed.
Sidewall generators have problems in the rain, and they wear out the tire. They are not the best solution.