Replace sqldelight with Room

This is a tool more Android devs are likely to be familiar with, let's try this out instead.

No files, tests, or entry points are named. Start by locating the existing SQLDelight integration and all database call sites, then determine the Room integration scope. Done means the template uses Room in place of SQLDelight and the existing database behavior remains covered by the project's checks.

索引モデルが issue の本文から書いたものです。