Async loading TypeScript by Integration (#3149)

The better implementation of #3139 using the dynamic `import()` instead
of `createRequire()`.

The new implementation requires either:
- to import and provide the `typescript` to `Integration::constructor()`
- or to use the new async method `Integration::create()`

This is a breaking change.

`typescript` becomes an optional peer dependency. Documentation adjusted
accordingly.

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

* **Documentation**
  * Updated README installation section to clarify TypeScript handling.
* Enhanced frontend client generation examples with explicit TypeScript
configuration instructions and usage patterns.

* **New Features**
* Added async factory method for integration setup, offering alternative
to direct instantiation.
* Made TypeScript an optional peer dependency instead of required,
reducing installation footprint.

<sub>✏️ Tip: You can customize this high-level summary in your review
settings.</sub>

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

Author: RobinTail

CHANGELOG.md

@@ -4,7 +4,32 @@
 
 ### v27.0.0
 
-- to be announced.
+- Breaking change to the `Integration` class:
+  - Either import and assign the `typescript` property to constructor argument;
+  - Or use the new static async method `create()` to delegate the import;
+
+```diff
+  /** Option 1: import and assign */
+  import { Integration } from "express-zod-api";
++ import typescript from "typescript";
+
+  const client = new Integration({
+    routing,
+    config,
++   typescript,
+  });
+```
+
+```diff
+  /** Option 2: delegate asynchronously */
+  import { Integration } from "express-zod-api";
+
+- const client = new Integration({
++ const client = await Integration.create({
+    routing,
+    config,
+  });
+```
 
 ## Version 26
 

README.md

@@ -180,7 +180,7 @@ Install the framework, its peer dependencies and type assistance packages using
 
 ```shell
 # example for pnpm:
-pnpm add express-zod-api express zod typescript http-errors
+pnpm add express-zod-api express zod http-errors
 pnpm add -D @types/express @types/node @types/http-errors
 ```
 
@@ -1074,13 +1074,15 @@ adding the runtime helpers the framework relies on.
 
 ## Generating a Frontend Client
 
-You can generate a Typescript file containing the IO types of your API and a client for it.
-Consider installing `prettier` and using the async `printFormatted()` method.
+You can generate a Typescript file containing the IO types of your API and a client for it. Make sure you have
+`typescript` installed. Consider also installing `prettier` and using the async `printFormatted()` method.
 
 ```ts
+import typescript from "typescript";
 import { Integration } from "express-zod-api";
 
 const client = new Integration({
+  typescript, // or await Integration.create() to delegate importing
   routing,
   config,
   variant: "client", // <— optional, see also "types" for a DIY solution

eslint.config.js

@@ -176,6 +176,10 @@ const tsFactoryConcerns = [
     selector: "Identifier[name='createUnionTypeNode']",
     message: "use makeUnion() helper",
   },
+  {
+    selector: "Identifier[name='createIdentifier']",
+    message: "use makeId() helper",
+  },
 ];
 
 export default tsPlugin.config(
@@ -238,11 +242,7 @@ export default tsPlugin.config(
     files: ["migration/index.ts"],
     rules: {
       "allowed/dependencies": ["error", { packageDir: migrationDir }],
-      "no-restricted-syntax": [
-        "warn",
-        ...importConcerns,
-        ...performanceConcerns,
-      ],
+      "no-restricted-syntax": ["warn", ...importConcerns],
     },
   },
   {

example/generate-client.ts

@@ -2,10 +2,12 @@ import { writeFile } from "node:fs/promises";
 import { Integration } from "express-zod-api";
 import { routing } from "./routing";
 import { config } from "./config";
+import typescript from "typescript";
 
 await writeFile(
   "example.client.ts",
   await new Integration({
+    typescript,
     routing,
     config,
     serverUrl: `http://localhost:${config.http!.listen}`,

express-zod-api/package.json

@@ -78,6 +78,9 @@
     },
     "express-fileupload": {
       "optional": true
+    },
+    "typescript": {
+      "optional": true
     }
   },
   "devDependencies": {