Add DMS configuration and helper scripts

- Introduced a new `justfile` for managing DMS-related tasks, including a recipe for syncing live DMS configuration.
- Added a `devshell.nix` file to set up a development environment with necessary packages and shell hooks for DMS.
- Updated DMS settings to replace `defaultSettingsFile` with `defaultSeedDir` for improved configuration management.
- Created a new script `sync-seed.sh` to facilitate syncing DMS settings from the live configuration to host-specific directories.
- Enhanced documentation and examples for DMS configuration and usage.

modules/hosts/14900k/configuration.nix

@@ -70,7 +70,7 @@
             ".#14900k"
           ];
           enableRbwLockToggle = true;
-          defaultSettingsFile = ./_private/dms-default-settings.json;
+          defaultSeedDir = ./_private/dms-defaults;
         };
       };