Document required external binaries in README

[f3rdy]

Description

The README's Install section currently only mentions the vaultctl binary itself. It does not mention the external binaries vaultctl shells out to, even though they are hard requirements for most operations.

This is a pre-existing gap. We close it now in preparation for #34, which adds another optional external binary (cue).

Required Additions

Add a "Required external tools" subsection under "## Install" listing:

• ansible-vault — handles the actual encryption/decryption (existing hard dependency).
• cue (optional, for schema validation, see Add CUE-based schema validation for vault files and config #34) — enables vaultctl validate and schema-checked imports. vaultctl will gracefully skip schema features if cue is not on \$PATH.

Files

• README.md

Priority

P3