Document that D1 binding has no per-call timeout option

src/content/docs/d1/observability/debug-d1.mdx

@@ -118,3 +118,25 @@ You should include as much of the following in any bug report:
 * Learn [how to debug Workers](/workers/observability/).
 * Understand how to [access logs](/workers/observability/logs/) generated from your Worker and D1.
 * Use [`wrangler dev`](/workers/wrangler/commands/general/#dev) to run your Worker and D1 locally and [debug issues before deploying](/workers/local-development/).
+
+## D1 binding timeout behavior
+
+D1 binding methods — `run()`, `all()`, `first()`, and `batch()` — do not accept a timeout option or an `AbortSignal`. There is no per-call timeout built into the D1 binding client.
+
+Workers have no wall-time limit on incoming HTTP requests while the client connection is open — see [Workers limits](/workers/platform/limits/). If the D1 database is temporarily unreachable, a D1 binding call blocks until the operation completes, an internal limit is reached, or the Worker is terminated by an external event such as the client disconnecting.
+
+To limit how long your Worker waits on a D1 call, use `Promise.race` with a timer:
+
+```js
+const timeout = new Promise((_, reject) =>
+  setTimeout(() => reject(new Error('D1 call timed out')), 5000)
+);
+const result = await Promise.race([
+  db.prepare('SELECT 1').first(),
+  timeout,
+]);
+```
+
+:::caution[Write operations and Promise.race]
+`Promise.race` bounds how long your Worker waits — it does not cancel the D1 query. A write that loses the race may still commit in the background. Always confirm the outcome of a write before retrying to avoid duplicate writes.
+:::