fix: enode field should contain node ID, not private key (#72)

## Summary

The `enode` field in `GeneratedNodeKey` was incorrectly set to the
private key instead of the node ID (public key with 0x04 prefix
stripped).

## Issues Fixed

- Individual validator enode ConfigMaps contained private keys instead
of node IDs
- Duplicate private key data (stored in both `privateKey` and `enode`
fields)
- Misleading ConfigMap names (`besu-node-validator-X-enode` contained
private key)

## Changes

1. **Fixed `src/keys/node-key-factory.ts`**: Strip the 0x04 prefix from
the public key to derive the node ID
2. **Fixed `src/keys/node-key-factory.test.ts`**: Updated test to
validate correct behavior (enode should be 128-char hex node ID)

## Testing

- ✅ All 90 tests pass
- ✅ Verified enode field now contains correct node ID format

## Note

This bug only affected the individual validator `enode` field. The
`static-nodes.json` generation was not affected because it used the
correct `deriveNodeId()` function.

## Links

- Bug in code:
https://github.com/settlemint/network-bootstrapper/blob/184bc9469aca3d08db69f8a0a9f4cf5ce6643deb/src/keys/node-key-factory.ts#L30
- Test that validated bug:
https://github.com/settlemint/network-bootstrapper/blob/184bc9469aca3d08db69f8a0a9f4cf5ce6643deb/src/keys/node-key-factory.test.ts#L15

## Summary by Sourcery

Fix incorrect enode field derivation by using the public key (node ID)
instead of the private key, and update tests to validate the new
behavior.

Bug Fixes:
- Derive enode node ID by stripping the 0x04 prefix from the
uncompressed public key instead of reusing the private key

Tests:
- Update NodeKeyFactory tests to assert enode is a 128-character hex
node ID without 0x prefix and unique per key

Author: saeeddawod

bun.lock

@@ -12,11 +12,16 @@ describe("NodeKeyFactory", () => {
     expect(first.privateKey.startsWith("0x")).toBe(true);
     expect(first.publicKey.startsWith("0x")).toBe(true);
     expect(first.address.startsWith("0x")).toBe(true);
-    expect(first.enode).toBe(first.privateKey);
+
+    // enode should be the node ID (public key with 0x04 prefix stripped)
+    expect(first.enode).toBe(first.publicKey.slice(4));
+    expect(first.enode).not.toContain("0x");
+    expect(first.enode.length).toBe(128); // 64 bytes hex-encoded
 
     expect(first.privateKey).not.toBe(second.privateKey);
     expect(first.publicKey).not.toBe(second.publicKey);
     expect(first.address).not.toBe(second.address);
+    expect(first.enode).not.toBe(second.enode);
   });
 
   test("throws on empty label", () => {

src/keys/node-key-factory.test.ts

@@ -20,14 +20,17 @@ export class NodeKeyFactory {
 
   /**
    * Generates a fresh private key alongside the derived public key, address,
-   * and exposes the private key again under `enode` for downstream tooling.
+   * and derives the node ID (enode) by stripping the 0x04 prefix from the uncompressed public key.
    */
   generate(): GeneratedNodeKey {
     const privateKey = generatePrivateKey();
     const account = privateKeyToAccount(privateKey);
     const publicKey = account.publicKey;
     const address = account.address;
-    const enode = privateKey;
+    // Derive node ID by stripping the 0x04 prefix from the uncompressed public key
+    const enode = publicKey.startsWith("0x04")
+      ? publicKey.slice(4)
+      : publicKey.slice(2);
 
     return {
       address,