CLI UX: 'axon version' should display meaningful version information

Problem

As a new user trying out Axon, running axon version only displays "latest", which is not helpful for:

1. Troubleshooting - Users can't tell maintainers what version they're running
2. Upgrade decisions - Can't determine if they need to upgrade
3. Verification - Can't verify their installation worked correctly

Current output:

$ axon version
latest

Expected Behavior

The version command should display meaningful information such as:

axon version v0.1.0
Git commit: f4b2c1d
Built: 2026-02-09T12:00:00Z
Go version: go1.23.4

Or at minimum:

axon v0.1.0 (f4b2c1d)

Context

Most CLI tools (kubectl, gh, docker, etc.) provide detailed version information including:

• Semantic version or release tag
• Git commit hash
• Build date
• Platform/architecture
• Go version (for Go tools)

This is especially important for open-source projects where users may be building from source or using different distribution channels.

Suggested Implementation

Use build-time flags to inject version information:

go build -ldflags "-X main.version=${VERSION} -X main.commit=${GIT_COMMIT} -X main.date=${BUILD_DATE}"

Start with the implementation of the axon version command and the Go build invocation that can receive -ldflags. Confirm how the current latest output is produced, then make the command report available version metadata such as the release version and commit; done means axon version no longer shows only latest.