Add rust-toolchain.toml with Rust 1.90 (#371)

* Add rust-toolchain.toml with Rust 1.90 and update docs

Co-authored-by: Mossaka <[email protected]>

* Remove wasm32-unknown-unknown target and revert doc version changes

Co-authored-by: Mossaka <[email protected]>

---------

Co-authored-by: copilot-swe-agent[bot] <[email protected]>
Co-authored-by: Mossaka <[email protected]>

Author: Copilot

CHANGELOG.md

@@ -6,6 +6,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 
 ### Added
 
+- `rust-toolchain.toml` file specifying Rust 1.90 as the stable toolchain version, ensuring consistent Rust version across development environments and CI/CD pipelines
 - AI agent development guides (`AGENTS.md` and `Claude.md`) that consolidate development guidelines from `.github/instructions/` into accessible documentation for AI agents working on the project
 - Comprehensive installation guide page consolidating all installation methods (one-liner script, Homebrew, Nix, WinGet) organized by platform (Linux, macOS, Windows) with verification steps and troubleshooting sections
 - Cookbook section in documentation with language-specific guides for building Wasm components in JavaScript/TypeScript, Python, Rust, and Go ([#328](https://github.com/microsoft/wassette/pull/328))

rust-toolchain.toml

@@ -0,0 +1,4 @@
+[toolchain]
+channel = "1.90"
+components = ["rustfmt", "clippy"]
+targets = ["wasm32-wasip2", "wasm32-wasip1"]