dead 2001 a4 avant - any troubleshooting advice?

Went to start the car this morning - dashboard lights, radio, headlights all work, but nothing when I turn the key - not even a click. Audi dealer recommended jumping, but the battery shows as fully charged, and doesn't seem to be the issue since all lights have power.

Before I have it towed 70+ miles to the dealer, I was hoping there might be something simple I could try ...

Car was fine yesterday - but did drive through some heavy rain.

Suggestions?

You did. If "mods" means modifications, the answer is no. I'm wondering if it is something with the clutch - I can't remember if the "Press Clutch" warning message usually goes off when I depress it to start, but it is not going off now.