Port PHP SDK route generation from nextlove to Metalsmith

Replace the @seamapi/nextlove-sdk-generator based generation with the
metalsmith + handlebars + @seamapi/blueprint architecture used by
seamapi/javascript-http and seamapi/python. The generated output under
src/ (SeamClient.php and Objects/*.php) is byte-identical.

The blueprint drives the route, endpoint, and namespace iteration order.
The raw OpenAPI spec is still consulted wherever the nextlove generator
derived output from data the blueprint normalizes differently (integer
vs number types, resource schema set and order, parameter and oneOf/allOf
flattening, deeply nested namespaces); each of those spots carries a TODO
to migrate to the blueprint once output is allowed to change, and the
supporting code lives in files marked TEMPORARY.

- Add codegen/ with the Metalsmith pipeline, plugin, context builders,
  and Handlebars layouts and partials
- Remove generate-routes.js
- Pin @seamapi/types at 1.827.0 for output parity and use
  @seamapi/blueprint 0.55.0 with @seamapi/smith
- Add tsconfig.json, a one-line eslint.config.ts, and typecheck, lint,
  postlint, and preformat scripts matching seamapi/docs
- Ignore *.hbs and CODEGEN.md in a new .prettierignore since the glimmer
  parser mangles PHP-flavored templates, and format .ts with the js rules
- Ignore the generated CODEGEN.md seed and *.tsbuildinfo in .gitignore

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UrUX4ghim2PDnBjXayuLDj

Author: claude

.gitignore

@@ -1,4 +1,10 @@
+# Codegen
+CODEGEN.md
+
 vendor
 node_modules
 .env
 .vscode
+
+# TypeScript cache
+*.tsbuildinfo

.prettierignore

@@ -0,0 +1,4 @@
+# Prettier exceptions
+
+*.hbs
+CODEGEN.md

.prettierrc.json

@@ -4,7 +4,7 @@
 
   "overrides": [
     {
-      "files": "**/*.{js,json,yml,md}",
+      "files": "**/*.{js,ts,json,yml,md}",
       "options": {
         "semi": false,
         "singleQuote": true,

codegen/content/CODEGEN.md

@@ -0,0 +1 @@
+# Codegen

codegen/index.ts

@@ -0,0 +1 @@
+export default null

codegen/layouts/default.hbs

@@ -0,0 +1 @@
+{{contents}}

codegen/layouts/object.hbs

@@ -0,0 +1,25 @@
+<?php
+
+namespace Seam\Objects;
+
+class {{className}}
+{
+    public static function from_json(mixed $json): {{className}}|null
+    {
+        if (!$json) {
+            return null;
+        }
+        return new self(
+{{#each fromJsonProps}}
+            {{{this}}}
+{{/each}}
+        );
+    }
+
+    public function __construct(
+{{#each constructorParams}}
+        {{{this}}}
+{{/each}}
+    ) {
+    }
+}

codegen/layouts/partials/client-class.hbs

@@ -0,0 +1,25 @@
+class {{clientName}}Client
+{
+  private SeamClient $seam;
+{{#if hasChildClients}}
+{{#each childClients}}
+  public {{clientName}}Client ${{namespace}};
+{{/each}}
+{{else}}
+
+{{/if}}
+  public function __construct(SeamClient $seam)
+  {
+    $this->seam = $seam;
+{{#each childClients}}
+    $this->{{namespace}} = new {{clientName}}Client($seam);
+{{/each}}
+  }
+{{#each methods}}
+
+{{> route-method}}
+{{/each}}
+{{#if isActionAttempts}}
+{{> poll-until-ready}}
+{{/if}}
+}

codegen/layouts/partials/poll-until-ready.hbs

@@ -0,0 +1,24 @@
+  public function poll_until_ready(string $action_attempt_id, float $timeout = 20.0): ActionAttempt
+  {
+    $seam = $this->seam;
+    $time_waiting = 0.0;
+    $polling_interval = 0.4;
+    $action_attempt = $seam->action_attempts->get($action_attempt_id);
+
+    while ($action_attempt->status == 'pending') {
+      $action_attempt = $seam->action_attempts->get(
+        $action_attempt->action_attempt_id
+      );
+      if ($time_waiting > $timeout) {
+        throw new ActionAttemptTimeoutError($action_attempt, $timeout);
+      }
+      $time_waiting += $polling_interval;
+      usleep($polling_interval * 1000000);
+    }
+
+    if ($action_attempt->status == 'error') {
+      throw new ActionAttemptFailedError($action_attempt);
+    }
+
+    return $action_attempt;
+  }

codegen/layouts/partials/route-method.hbs

@@ -0,0 +1,44 @@
+    public function {{methodName}}({{{signatureParams}}}): {{returnType}} {
+{{#if hasParams}}
+        $request_payload = [];
+
+{{#each paramNames}}
+        if (${{this}} !== null) {
+            $request_payload["{{this}}"] = ${{this}};
+        }
+{{/each}}
+
+{{/if}}
+        {{#unless returnsVoid}}$res = {{/unless}}$this->seam->request(
+            "POST",
+            "{{path}}",
+{{#if hasParams}}
+            json: (object) $request_payload,
+{{/if}}
+        );
+{{#if usesActionAttempt}}
+
+        if (!$wait_for_action_attempt) {
+            return {{returnResource}}::from_json($res->{{returnPath}});
+        }
+
+        $action_attempt = $this->seam->action_attempts->poll_until_ready($res->action_attempt->action_attempt_id);
+
+        return $action_attempt;
+{{else}}
+{{#if usesOnResponse}}
+
+        if ($on_response !== null) {
+            $on_response($res);
+        }
+{{/if}}
+{{#unless returnsVoid}}
+
+{{#if isArrayResponse}}
+        return array_map(fn ($r) => {{returnResource}}::from_json($r), $res->{{returnPath}});
+{{else}}
+        return {{returnResource}}::from_json($res->{{returnPath}});
+{{/if}}
+{{/unless}}
+{{/if}}
+    }