chore(lint): add registerHttpHandler usage guard script

scripts/check-no-register-http-handler.mjs

@@ -0,0 +1,38 @@
+#!/usr/bin/env node
+
+import ts from "typescript";
+import { runCallsiteGuard } from "./lib/callsite-guard.mjs";
+import { runAsScript, toLine, unwrapExpression } from "./lib/ts-guard-utils.mjs";
+
+const sourceRoots = ["src", "extensions"];
+
+function isDeprecatedRegisterHttpHandlerCall(expression) {
+  const callee = unwrapExpression(expression);
+  return ts.isPropertyAccessExpression(callee) && callee.name.text === "registerHttpHandler";
+}
+
+export function findDeprecatedRegisterHttpHandlerLines(content, fileName = "source.ts") {
+  const sourceFile = ts.createSourceFile(fileName, content, ts.ScriptTarget.Latest, true);
+  const lines = [];
+  const visit = (node) => {
+    if (ts.isCallExpression(node) && isDeprecatedRegisterHttpHandlerCall(node.expression)) {
+      lines.push(toLine(sourceFile, node.expression));
+    }
+    ts.forEachChild(node, visit);
+  };
+  visit(sourceFile);
+  return lines;
+}
+
+export async function main() {
+  await runCallsiteGuard({
+    importMetaUrl: import.meta.url,
+    sourceRoots,
+    findCallLines: findDeprecatedRegisterHttpHandlerLines,
+    header: "Found deprecated plugin API call registerHttpHandler(...):",
+    footer:
+      "Use registerHttpRoute({ path, auth, match, handler }) and registerPluginHttpRoute for dynamic webhook paths.",
+  });
+}
+
+runAsScript(import.meta.url, main);