Add queue tables, quote SQL identifiers (v1.3.0)

- isQueue table option adds queue columns and a (status, available_at)
  index; BunSQLite.queue exposes add, claim, complete, fail and
  release_stale with atomic claims
- Set busy_timeout on connections so workers in separate processes wait
  instead of failing with SQLITE_BUSY
- Quote table and column names with backticks in generated SQL, so
  reserved words (to, order, group) work and unknown columns error
  instead of matching as string literals
- Tests for queue ops, multi-process claims and reserved-word names

Co-Authored-By: Claude Opus 5.5 <[email protected]>

tests/fixtures/queue-worker.ts

@@ -0,0 +1,42 @@
+/**
+ * Queue worker for the multi-process claim test. Claims jobs one at a time
+ * until the queue is empty and prints the claimed ids as JSON.
+ */
+import fs from "fs";
+import path from "path";
+import grabSQLiteClient from "../../src/functions/grab-sqlite-client";
+import { QueueClaim, QueueComplete } from "../../src/lib/sqlite/db-queue";
+import type { BunSQLiteConfig, BUN_SQLITE_DatabaseSchemaType } from "../../src/types";
+
+const config: BunSQLiteConfig = JSON.parse(process.env.QUEUE_TEST_CONFIG!);
+const dbSchema: BUN_SQLITE_DatabaseSchemaType = JSON.parse(
+    process.env.QUEUE_TEST_SCHEMA!,
+);
+const worker = process.env.QUEUE_TEST_WORKER!;
+
+global.CONFIG = config;
+global.DB_SCHEMA = dbSchema;
+global.SQLITE_CLIENT = grabSQLiteClient({ config });
+
+// Signal ready, then wait for the test to start every worker at once
+fs.writeFileSync(path.join(config.db_dir!, `ready-${worker}`), "");
+while (!fs.existsSync(path.join(config.db_dir!, "go"))) {}
+
+const ids: number[] = [];
+
+while (true) {
+    const res = await QueueClaim({ table: "jobs", worker });
+
+    if (!res.success) {
+        console.error(res.error);
+        process.exit(1);
+    }
+
+    const job = res.singleRes;
+    if (!job) break;
+
+    ids.push(job.id);
+    await QueueComplete({ table: "jobs", id: job.id });
+}
+
+console.log(JSON.stringify(ids));