Add a new shell function that uses an LLM API to generate shell commands
from natural language queries. The command displays the generated command
for user confirmation before execution and adds it to history.
- Generates shell commands from natural language via LLM
- Displays command for user review before execution
- Automatically adds executed commands to bash history
- Uses qwen3-coder-next-80b-instruct model
Upgrade the NixOS `stateVersion` from 25.05 to 25.11 in all system configuration files and update all nix channel URLs to the 25.11 releases. Adjust Home Manager and terminal module configurations accordingly, clean up duplicated SSH keys, and update LLaMA server command lines. Minor housekeeping changes to package definitions and other configuration files are also included.
