chore: release v0.5.0

[github-actions]

🤖 New release

• tinybox: 0.4.1 -> 0.5.0 (⚠ API breaking changes)

⚠ tinybox breaking changes

--- failure repr_c_removed: repr(C) removed ---

Description:
repr(C) was removed from a type. This can cause its memory layout to change, breaking FFI use cases.
        ref: https://doc.rust-lang.org/cargo/reference/semver.html#repr-c-remove
       impl: https://github.com/obi1kenobi/cargo-semver-checks/tree/v0.50.0/src/lints/repr_c_removed.ron

Failed in:
  struct TinyBoxSized in /tmp/.tmpyoceG1/tinybox-rs/src/lib.rs:53

Changelog

0.5.0 - 2026-10-08

Fixed

• allow coercion in unstable

Other

• document public items

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This PR was generated with release-plz.