Totally onboard with the idea of sprouting seeds, MarigoldBreeze. These lil' guys are nutritional powerhouses and can provide a continuous food source if managed right. I've been sprouting mung beans and lentils for years, quite the lifesaver they are.
Quick note: when you're considering your shelter's structural rigidity, don't forget to think about blast protection. A good blast door can prevent pressure changes from affecting the integrity of your shelter. I've heard good things about steel or composite blast doors.
While we're at it, have you given thought to air filtration systems? Staying underground for extended periods without adequate ventilation can be bad for health. Something to ponder, yeah?
And, just a tip from experience, keep a well-stocked medical kit. Doesn't need to be fancy; basics like bandages, disinfectants, basic meds. You never know what might crop up when you're hunkered down. Makes sense, doesn't it?