deps(rust-core): Update uniffi requirement from 0.31.0 to 0.32.0 in /rust/letterbox-core in the rust-core group across 1 directory

[dependabot]

Updates the requirements on uniffi to permit the latest version.
Updates uniffi to 0.32.0

Changelog

Sourced from uniffi's changelog.

v0.32.0 (backend crates: v0.32.0) - (2026-06-30)

⚠️ Breaking Changes ⚠️

• Kotlin and Python now fail to generate bindings when there are async primary constructors. Previously these languages skipped the constructor in this case or generated a constructor that always threw. You can get similar behavior by adding the primary constructor to the uniffi.toml excludes list in uniffi.toml (e.g. `excludes = ["MyObject.new"])
• Ruby: Force named parameters for enum constructors (#2880)
• The --config flag now expects a global config file rather than a flat uniffi.toml-style override. Old-style files will produce a warning and be ignored. See #2866
• [ByRef] bytes UDL arguments now map to &[u8] on the Rust side instead of &Vec<u8>. UDL-defined functions whose Rust implementations take &Vec<u8> must change to &[u8]. Proc-macro signatures (fn foo(x: &[u8])) are unchanged. On the Kotlin side, call sites must now pass a direct java.nio.ByteBuffer rather than ByteArray; migrate with ByteBuffer.allocateDirect(arr.size).put(arr).flip(). Swift (Data) and Python (bytes) call sites are unchanged. (#2878)
• Reworked the experimental pipeline bindgen code. Any external binding generators using this will need to be reworked as well. See #2787 for examples of how this can be done.

⚠️ Breaking Changes for external bindings authors ⚠️

• The signature for CrateConfigSupplier::from_cargo_metadata_command has changed. It now inputs a MetadataCommand instance and a CargoMetadataOptions rather than just a no_deps flag.

What's Fixed

• Fixed bug that sometimes prevented renaming items inside a submodule #2792
• Exempted UniFfiTag from clippy::exhaustive_structs since downstream projects may depend on it #2809
• Fixed compile errors when exporting ambiguous method names #2937
• Ruby: Code for all kinds of enums and custom types is now correctly generated #2880 and #2891

⚠️ Breaking Changes for external bindings authors ⚠️

• There's a new GlobalConfig struct for managing config. It replaces BindgenPathsLayer::get_config() method which has been removed. See #2866.
• [ByRef] bytes arguments now travel across the FFI as a ForeignBytes (pointer + length) value rather than a RustBuffer. External bindings need to accept the foreign-language byte buffer at the call site and lower it to ForeignBytes for the duration of the call (no copy). (#2878)

What's New?

• Global config file support via --config. See the docs.

• Traits can now be exported with #[uniffi::export(foreign)] for foreign-only implementations, or #[uniffi::export(rust, foreign)] for both Rust and foreign implementations. The with_foreign flag is deprecated in favor of rust, foreign.

• Recursive enums are now supported. UniFFI automatically detects when enum and record types participate in cycles — self-referential, mutually recursive, or cycling through a record — and generates appropriate bindings: indirect in Swift, forward references in Python (#2834).

• Box<T> now automatically implements FFI traits when T implements them, allowing direct use in enum variants and function parameters without NewType wrappers (#2808)

• Record fields can now be renamed with the proc-macro name = "new_field_name" attribute (#2794)

• Items can be excluded from the generated bindings using uniffi.toml.

• Added mutable_records configuration option to allow specific records to remain mutable even when generate_immutable_records is enabled (Kotlin and Swift).

• Kotlin objects now have an uniffiIsDestroyed property that returns true if the Rust reference no longer exists (#2825)

• Updated askama version to 0.15.6

• Custom Types can have docstrings in some languages (#2853)

• Ruby: Expose standard Rust traits for generated ruby code (#2883)

• Ruby: Add support for sync foreign traits (#2916)

• Ruby: Add async support (#2923)

• Added zero-copy transfer of &[u8] / [ByRef] bytes arguments from foreign code to Rust. Kotlin (java.nio.ByteBuffer, must be direct), Swift (Data), and Python (bytes-like, buffer protocol) pass byte buffers as pointer + length (ForeignBytes) rather than copying through RustBuffer. Not yet supported on Ruby, and not yet supported in async functions on any language (#2878).

• #[uniffi::export(async_runtime = "tokio")] can now be applied to trait exports, wrapping each method's FFI scaffolding future in async_compat::Compat the same way it does for inherent impls and free functions (#2899).

• Added support for using HashSet with proc-macros

... (truncated)

Commits

• 5c7b739 chore: Release
• c4ec9d8 chore: Release
• 7d647a8 Benchmark tables
• ad9b725 Pipeline IDs
• 0f6a2bc Allow literal number suffix for uniffi::Enum (#2926)
• bc38ff4 Merge pull request #2927 from bendk/bdk/push-komxvuvksmqu
• 046d894 Merging changes from 0.31.2 back to main
• afd83b2 Loosen toml semver for uniffi_macros
• 418ab38 add async support for ruby
• 05b45b1 chore: Release
• Additional commits viewable in compare view