perf(db): enable auto-vacuum and add periodic maintenance

Author: BYK

packages/opencode/src/storage/db.ts

@@ -93,6 +93,14 @@ export const Client = lazy(() => {
   db.run("PRAGMA foreign_keys = ON")
   db.run("PRAGMA wal_checkpoint(PASSIVE)")
 
+  // One-time auto-vacuum migration: switch from none (0) to incremental (2)
+  const autoVacuum = db.$client.prepare("PRAGMA auto_vacuum").get() as { auto_vacuum: number } | undefined
+  if (autoVacuum?.auto_vacuum === 0) {
+    log.info("enabling incremental auto_vacuum")
+    db.run("PRAGMA auto_vacuum = 2")
+    db.run("VACUUM")
+  }
+
   // Apply schema migrations
   const entries =
     typeof OPENCODE_MIGRATIONS !== "undefined"
@@ -170,3 +178,11 @@ export function transaction<T>(
     throw err
   }
 }
+
+export function checkpoint() {
+  Client().$client.run("PRAGMA wal_checkpoint(TRUNCATE)")
+}
+
+export function vacuum() {
+  Client().$client.run("PRAGMA incremental_vacuum")
+}