FRB v2
======
With flutter_rust_bridge, the Rust dependency lives in Cargo.toml, not pubspec.yaml

FRB v2 ships with Cargokit — a build helper that hooks into each platform's build 
system (Gradle, Xcode, CMake) and compiles the Rust crate automatically at flutter build time. 
This means:
  * ccc_rust does not need a pubspec.yaml
  * ccc_rust stays a pure Rust crate
  * The current lum_ccc_rust entry in pubspec.yaml would be removed — it moves to rust/Cargo.toml

::

  ccc_dart_plugin/
  ├── pubspec.yaml          ← NO reference to ccc_rust here
  ├── rust/
  │   ├── Cargo.toml        ← ccc_rust referenced HERE as a Rust crate dep
  │   └── src/api.rs        ← thin wrappers calling ccc_rust


ccc_rust
========
The Rust crypto library remains a pure Rust crate with no Flutter or FFI-specific code.
Option 1: Build from source via Cargokit (recommended for development)
  * The Rust crate references ccc_rust via a git tag in Cargo.toml
  * Cargokit compiles the Rust code at build time for each platform
  * No precompiled binaries are needed

Option 2: Cargokit precompiled binaries via GitHub Releases (recommended for pub.dev)
  * The Rust crate is compiled into platform-specific binaries (staticlib for iOS/macOS, cdylib for Android)
  * Binaries are uploaded to GitHub Releases
  * Cargokit fetches the correct binary at build time based on the target platform
  * This allows pub.dev users to get native performance without needing Rust or a build environment


Workflow
--------
* CI builds the Rust crate for all 5 platform targets
* CI uploads the .so/.dylib/.dll/.framework to a GitHub Release tagged with the Cargo package hash
* When consumers run flutter build, Cargokit downloads the precompiled binary instead of compiling
* If no precompiled binary exists, it falls back to source build
* Pros: Fast builds for consumers, no Rust toolchain needed, no repo bloat, built into FRB, single repo
* Cons: Requires CI pipeline to build + upload binaries
* Best for: pub.dev releases, distributing to teams without Rust installed