requestConfig was assuming that the order of fields in meshtastic.LocalConfig
matches the order of enum values in AdminMessage.ConfigType. This is true for
'device', 'position', etc. but is NOT true for 'security' due to the intervening
'version' field.
Look up LocalConfig fields by name, not index, to prevent this error in the future.
LocalConfig.security was introduced in https://github.com/meshtastic/protobufs/pull/553
this function, xor_hash, and a variable for the default key (as bytes, I think, rather than the base64 version) really all belong in meshtastic.util rather than here.
There's multiple forms of hashing in firmware so this should be named to denote that, perhaps channel_hash. If we later want to add the frequency-slot-style hash, better if it's distinguished better from the start.
### Summary
- Added a new method `get_channels_with_hash()` to the `Node` class.
- This method returns a list of dictionaries, each containing the channel index, role, name, and a hash value derived from the channel name and PSK.
- The hash is calculated using the existing `generate_hash` utility, ensuring consistency with other parts of the codebase.
- This utility makes it easier to programmatically access channel metadata, including a unique hash, for scripting, debugging, or integration purposes.
### Motivation
- The protobuf `Channel` objects do not include a hash value by default.
- This addition provides a Pythonic, easy-to-use way to access channel info and a unique hash for each channel, which can be useful for diagnostics, scripting, or UI display.
### Example Usage
```python
channels = node.get_channels_with_hash()
for ch in channels:
print(f"Index {ch['index']}: {ch['role']} name='{ch['name']}' hash={ch['hash']}")
```
### Impact
- No breaking changes; existing APIs and CLI output remain unchanged.
- The new method is additive and can be used where needed for enhanced channel introspection.
