Node Discovery IPv6 support

[tkam8]

Summary

The Node Discovery wizard in the frontend fails to accept valid IPv6 addresses, throwing an Invalid IP address: error.

The validation logic in frontend-v2/src/lib/ip-range.ts specifically expects a 4-octet IPv4 format and splits strings using the . character. When an IPv6 address (e.g., 2020:ab1:1010::81) is parsed, it evaluates to null because it uses colons (:) instead of dots,
triggering the validation error.

Severity

Low

Steps to Reproduce

1. Navigate to Build > Projects > Discovery > Node Discovery > Host IP Addresses.
2. Enter a valid IPv6 address (e.g., `2020:ab1:1010::81`).
3. Observe the validation error: `Invalid IP address: 2020:ab1:1010::81`.

Expected Behavior

The wizard should recognize valid IPv6 addresses as acceptable input and not throw an invalid IP error.

Suggested Fix

Update the validation logic in `frontend-v2/src/lib/ip-range.ts` to include regex validation for IPv6 addresses before falling back to the error state. 

Location: frontend-v2/src/lib/ip-range.ts

Code change:

```typescript
// 1. Add this helper function
function isIpv6(value: string): boolean {
  const regexString =
    '^(' +
    '([0-9a-fA-F]{1,4}:){7,7}[0-9a-fA-F]{1,4}|' +
    '([0-9a-fA-F]{1,4}:){1,7}:|' +
    '([0-9a-fA-F]{1,4}:){1,6}:[0-9a-fA-F]{1,4}|' +
    '([0-9a-fA-F]{1,4}:){1,5}(:[0-9a-fA-F]{1,4}){1,2}|' +
    '([0-9a-fA-F]{1,4}:){1,4}(:[0-9a-fA-F]{1,4}){1,3}|' +
    '([0-9a-fA-F]{1,4}:){1,3}(:[0-9a-fA-F]{1,4}){1,4}|' +
    '([0-9a-fA-F]{1,4}:){1,2}(:[0-9a-fA-F]{1,4}){1,5}|' +
    '[0-9a-fA-F]{1,4}:((:[0-9a-fA-F]{1,4}){1,6})|' +
    ':((:[0-9a-fA-F]{1,4}){1,7}|:)' +
    ')$';
  return new RegExp(regexString).test(value);
}

// 2. Update expandIpToken to check for either IPv4 or IPv6
export function expandIpToken(token: string): ExpandResult {
  const trimmed = token.trim();
  if (!trimmed) return { ips: [], errors: [] };

  if (!trimmed.includes('-')) {
    if (parseIp(trimmed) !== null || isIpv6(trimmed)) {
      return { ips: [trimmed], errors: [] };
    }
    return { ips: [], errors: [`Invalid IP address: ${trimmed}`] };
  }
  // ... rest of the function for IPv4 ranges
}
```