v0.7.0

Fixed

• Render the cover image media-type in the package document; it was always empty.
• Run CI on main — the workflow still targeted the removed master branch, so it never ran.

Changed

• Breaking: BUPE.build/3 now returns the output path as a String.t() instead of a charlist.
• Breaking: requires Elixir ~> 1.17 and Erlang/OTP 27+.
• Test against an Elixir/OTP matrix in CI, plus Credo, Dialyzer, hex.audit, format, and unused-deps checks.
• Remove the deprecated build_embedded project option.

Full Changelog: v0.6.5...v0.7.0