revert: remove SQLite support

An MMO server without multiplayer defeats the purpose. PostgreSQL
is the right choice and Docker Compose already solves the setup
pain. This reverts the common/db wrapper, SQLite schema, config
Driver field, modernc.org/sqlite dependency, and all repo type
changes while keeping the dashboard, wizard, and CI improvements
from the previous commit.

server/channelserver/repo_user_test.go

@@ -2,7 +2,6 @@ package channelserver
 
 import (
 	"database/sql"
-	dbutil "erupe-ce/common/db"
 	"testing"
 	"time"
 
@@ -13,7 +12,7 @@ func setupUserRepo(t *testing.T) (*UserRepository, *sqlx.DB, uint32) {
 	t.Helper()
 	db := SetupTestDB(t)
 	userID := CreateTestUser(t, db, "user_repo_test")
-	repo := NewUserRepository(dbutil.Wrap(db))
+	repo := NewUserRepository(db)
 	t.Cleanup(func() { TeardownTestDB(t, db) })
 	return repo, db, userID
 }