kevmurr lets you pin where Mike's files actually live

Storage for a Mike deployment runs on Cloudflare R2, an object-storage service for files and documents. Until now the region was effectively fixed, leaving operators to edit source code if they needed something specific. kevmurr's change makes the storage region a setting an operator can choose at deployment time, while leaving the existing default untouched for anyone who doesn't care.

The reason this matters isn't technical housekeeping. Some storage configurations - particularly buckets tied to a specific jurisdiction - only work when you can name the region explicitly. This change makes that possible without forking the code, so a firm that needs its documents to sit in a particular place can say so.