feat: schéma Drizzle/SQLite (machines, snapshots, executions)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

drizzle.config.ts

@@ -0,0 +1,7 @@
+import { defineConfig } from "drizzle-kit";
+
+export default defineConfig({
+  dialect: "sqlite",
+  schema: "./server/db/schema.ts",
+  out: "./server/db/migrations",
+});