refactor: complete TypeScript migration and add synchronous API with security hardening

- Remove all JavaScript source files and legacy tests
- Add synchronous versions of sign and verify functions
- Reorganize test structure into unit tests with TypeScript
- Update build configuration for dual CommonJS/ESM support
- Add shared utility modules for better code organization
- Improve algorithm implementations with better type safety
- Enhance security with stricter input validation and error handling
- Harden against timing attacks in signature verification
- Add comprehensive type guards for JWT payload validation
- Update documentation with new API references

BREAKING CHANGE: This completes the v10 migration to TypeScript with new synchronous APIs and reorganized module structure

Author: interpret-tech

MIGRATION_GUIDE_V10.md

@@ -15,17 +15,18 @@ npm install jsonwebtoken
 
 ## Documentation
 
-📚 **[View the complete documentation in our Wiki](https://github.com/auth0/node-jsonwebtoken/wiki)**
+📚 **[View the complete documentation in our Wiki](https://github.com/interpret-tech/node-jsonwebtoken/wiki)**
 
 The Wiki includes:
-- [Getting Started Guide](https://github.com/auth0/node-jsonwebtoken/wiki/Installation-&-Setup)
-- [API Reference](https://github.com/auth0/node-jsonwebtoken/wiki)
-- [Migration Guides](https://github.com/auth0/node-jsonwebtoken/wiki/Migration-Guide-v10)
-- [TypeScript Examples](https://github.com/auth0/node-jsonwebtoken/wiki/Usage-Examples#typescript-examples)
-- [Security Best Practices](https://github.com/auth0/node-jsonwebtoken/wiki/Security-&-Algorithms)
+- [Getting Started Guide](https://github.com/interpret-tech/node-jsonwebtoken/wiki/Installation-&-Setup)
+- [API Reference](https://github.com/interpret-tech/node-jsonwebtoken/wiki)
+- [Migration Guides](https://github.com/interpret-tech/node-jsonwebtoken/wiki/Migration-Guide-v10)
+- [TypeScript Examples](https://github.com/interpret-tech/node-jsonwebtoken/wiki/Usage-Examples#typescript-examples)
+- [Security Best Practices](https://github.com/interpret-tech/node-jsonwebtoken/wiki/Security-&-Algorithms)
 
 ## Quick Start
 
+### Asynchronous (Promise-based)
 ```javascript
 const jwt = require('jsonwebtoken');
 
@@ -37,6 +38,34 @@ const decoded = await jwt.verify(token, 'secret');
 console.log(decoded.foo) // 'bar'
 ```
 
+### Synchronous
+```javascript
+const jwt = require('jsonwebtoken');
+
+// Sign a token
+const token = jwt.signSync({ foo: 'bar' }, 'secret');
+
+// Verify a token
+const decoded = jwt.verifySync(token, 'secret');
+console.log(decoded.foo) // 'bar'
+```
+
+### Callback-based
+```javascript
+const jwt = require('jsonwebtoken');
+
+// Sign a token
+jwt.sign({ foo: 'bar' }, 'secret', (err, token) => {
+  if (err) throw err;
+  
+  // Verify the token
+  jwt.verify(token, 'secret', (err, decoded) => {
+    if (err) throw err;
+    console.log(decoded.foo) // 'bar'
+  });
+});
+```
+
 ## Requirements
 
 - **Node.js** >= 20

MIGRATION_SUMMARY.md

@@ -1,12 +1,12 @@
 module.exports = [
   {
-    ignores: ["node_modules/**", "coverage/**", "dist/**", ".nyc_output/**"]
+    ignores: ["node_modules/**", "coverage/**", "dist/**", ".nyc_output/**", "convert-tests-to-async.js"]
   },
   {
     files: ["**/*.js"],
     languageOptions: {
       ecmaVersion: 2022,
-      sourceType: "commonjs",
+      sourceType: "script",
       globals: {
         Buffer: "readonly",
         process: "readonly",
@@ -42,6 +42,18 @@ module.exports = [
       "object-shorthand": ["warn", "always"]
     }
   },
+  {
+    files: ["test/compatibility-esm.test.js"],
+    languageOptions: {
+      ecmaVersion: 2022,
+      sourceType: "module",
+      globals: {
+        Buffer: "readonly",
+        process: "readonly",
+        console: "readonly"
+      }
+    }
+  },
   {
     files: ["test/**/*.js"],
     languageOptions: {