fix: auto-apply DB schema on fresh install and fix admin registration (#81)

- Auto-apply schema.sql when database tables don't exist (embedded in binary)
- Handle missing tables gracefully during admin registration (treat as fresh install)
- Fix docker-compose depends_on to wait for postgres healthcheck
- Rename personal folder from 'Mi Carpeta' to 'My Folder' with backward compat
- Translate remaining Spanish messages to English

Cargo.lock

@@ -1686,7 +1686,7 @@ checksum = "42f5e15c9953c5e4ccceeb2e7382a716482c34515315f7b03532b8b4e8393d2d"
 
 [[package]]
 name = "oxicloud"
-version = "0.3.0"
+version = "0.3.1"
 dependencies = [
  "anyhow",
  "argon2",