feat(cli): make media-use a first-class command

[miguel-heygen]

Summary

• move the media-use engine and its tests under the CLI source tree
• add hyperframes media-use subcommands with the existing flags and output
• ship bundled media-use assets in the CLI distribution and keep the old resolve path as a compatibility shim

Verification

• devbox CLI package build
• moved media-use suite: 288 passed
• built CLI smoke: media-use resolve --type sfx --intent click --local-only --json resolves the bundled click asset
• regenerated skills manifest