Feat: Add AGENTS.md for AI development guidelines

This commit adds the AGENTS.md file, which was missed in the previous commit.

It includes guidelines for AI agents working on this repository, covering:
- Project overview and key technologies.
- Development workflow (coding, documentation, testing, linting).
- Important conventions, especially around Durable Object operation synchronicity.
- Code structure highlights.

Author: google-labs-jules[bot]

docs/databases/do.md

@@ -41,14 +41,15 @@ export class MyDurableObject extends DurableObject {
 
     // It's common to run schema migrations or table creations in the constructor,
     // wrapped in blockConcurrencyWhile to ensure they complete before other operations.
-    this.ctx.blockConcurrencyWhile(async () => {
-      await this.initializeDB();
+    // Operations inside blockConcurrencyWhile are synchronous with respect to DO storage.
+    this.ctx.blockConcurrencyWhile(() => {
+      this.initializeDB();
     });
   }
 
-  async initializeDB() {
+  initializeDB() {
     // Example: Create table if it doesn't exist
-    // Note: .execute() is synchronous for DOQB, but blockConcurrencyWhile expects a Promise
+    // .execute() is synchronous for DOQB.
     this.#qb.createTable({
         tableName: 'items', // Example table
         ifNotExists: true,
@@ -95,7 +96,8 @@ export class MyDurableObject extends DurableObject {
     super(state, env);
     this.#qb = new DOQB(this.storage.sql);
 
-    this.ctx.blockConcurrencyWhile(async () => {
+    // Operations inside blockConcurrencyWhile are synchronous with respect to DO storage.
+    this.ctx.blockConcurrencyWhile(() => {
       // Create table (if not exists) - good practice in constructor
       this.#qb.createTable({
           tableName: 'items',

docs/migrations.md

@@ -89,16 +89,17 @@ export class MyDurableObject extends DurableObject {
     super(state, env);
 
     this.#qb = new DOQB(this.ctx.storage.sql);
-    void this.ctx.blockConcurrencyWhile(async () => {
+    void this.ctx.blockConcurrencyWhile(() => {
       // Assuming 'migrations' is an array of Migration objects defined elsewhere
       const migrationBuilder = this.#qb.migrations({ migrations });
-      await migrationBuilder.apply(); // Ensure apply is awaited
+      migrationBuilder.apply(); // Operations within blockConcurrencyWhile are synchronous
     });
   }
 
-  async getUsers(): Promise<Array<object>> {
+  getUsers(): Array<object> {
     // Example method, ensure migrations are applied before accessing tables
-    return this.#qb.select('users').all().results
+    // Operations within Durable Objects are generally synchronous after the initial setup.
+    return this.#qb.select('users').all().results;
   }
 }
 ```