v0.4.0

What's Changed

• feat(cli): workflow group — ls + describe by @mostlymaxi in #5
• ci(pages): publish docs site on v* tags by @mostlymaxi in #8
• feat(cli): cargo athena submit by @mostlymaxi in #6
• feat(nix): flake package + app for the CLI by @mostlymaxi in #9
• test(e2e): full feature matrix on real Argo + fix fan_out aggregate by @mostlymaxi in #10
• nix: fenix toolchain, substituted from nix-community cachix by @mostlymaxi in #11
• deps: examples consume cargo-athena lean (default-features=false) by @mostlymaxi in #13
• docs: drop a stale CLAUDE.md convention bullet by @mostlymaxi in #12
• feat(cli): implement cargo athena publish by @mostlymaxi in #14
• docs: correctness sweep + new-user flow polish by @mostlymaxi in #15
• chore: bump to v0.4.0 by @mostlymaxi in #16

Full Changelog: v0.3.0...v0.4.0