fix: package.json missing 'type': 'module' inconsistent with AGENTS.md (#850)

Update tsconfig.json to use NodeNext module system (fixes CJS/ESM conflict),
enable ts-node ESM mode, and add .js extensions to relative imports so the
built output and ts-node dev script both work correctly with "type":"module".

tools/push3-transpiler/src/index.ts

@@ -10,8 +10,8 @@
 
 import * as fs from 'fs';
 import * as path from 'path';
-import { parse } from './parser';
-import { transpile } from './transpiler';
+import { parse } from './parser.js';
+import { transpile } from './transpiler.js';
 
 function main(): void {
   const args = process.argv.slice(2);

tools/push3-transpiler/src/transpiler.ts

@@ -8,7 +8,7 @@
  * Only the subset of instructions used in optimizer_v3.push3 is implemented.
  */
 
-import { Node } from './parser';
+import { Node } from './parser.js';
 
 interface TranspilerState {
   dStack:    string[];              // DYADIC stack (Solidity expressions)

tools/push3-transpiler/tsconfig.json

@@ -1,8 +1,9 @@
 {
   "compilerOptions": {
-    "target": "ES2020",
-    "module": "commonjs",
-    "lib": ["ES2020"],
+    "target": "ES2022",
+    "module": "NodeNext",
+    "moduleResolution": "NodeNext",
+    "lib": ["ES2022"],
     "outDir": "dist",
     "rootDir": "src",
     "strict": true,
@@ -10,6 +11,9 @@
     "skipLibCheck": true,
     "resolveJsonModule": true
   },
+  "ts-node": {
+    "esm": true
+  },
   "include": ["src/**/*"],
   "exclude": ["node_modules", "dist"]
 }