release: bump version to v0.3.0 (#755)

Bump version string from 0.2.18 to 0.3.0 and set CHANGELOG date to
2026-03-30. This is the final step of the v0.3.0 release prep.

Signed-off-by: Carlos Eduardo Arango Gutierrez <eduardoa@nvidia.com>

Author: ArangoGutierrez

CHANGELOG.md

@@ -2,7 +2,7 @@
 
 All notable changes to this project will be documented in this file.
 
-## [v0.3.0] - Unreleased
+## [v0.3.0] - 2026-03-30
 
 ### Features
 

cmd/cli/main.go

@@ -94,7 +94,7 @@ Examples:
 
   # Use a custom cache directory
   holodeck --cachepath /path/to/cache create -f env.yaml`
-	c.Version = "0.2.18"
+	c.Version = "0.3.0"
 	c.EnableBashCompletion = true
 
 	// Setup the flags for this command