docs(rivetkit): add rust quickstart preview

[NathanFlurry]

Adds a dedicated RivetKit Rust quickstart marked as preview.

Documents how to build/run the local rivet-engine, start the examples/rust-counter runtime with rivetkit-core, create a counter actor, call actions, and run the example e2e test.

[NathanFlurry]

Stack for rivet-dev/rivet

• fix(depot): fix migrating v1 -> v2 databases #5183 mxwxqyss · 2026-06-05 23:09:16
• docs(rivetkit): add rust quickstart preview #5182 lpzwyzmw · 2026-06-05 23:09:15 👈
• feat(rivetkit): add rust counter example #5181 mtrynmln · 2026-06-05 23:09:14
• refactor(depot): remove sqlite cold storage #5180 oxsukmwr · 2026-06-05 23:09:13
• main

Check out this stack: jj-stack get https://github.com/rivet-dev/rivet/pull/5182
Pull/update this stack: jj-stack sync
Publish local edits: jj-stack submit
Merge when ready: jj-stack merge

[claude]

PR Review: Rust Quickstart Documentation

This PR adds a new Rust quickstart guide for RivetKit, integrating it into both the main quickstart page and the actors quickstart page.

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Strengths

• Well-structured 6-step guide with clear progression from setup to testing
• Navigation integration is consistent: faRust icon imported and used across both quickstart pages and the sitemap
• Preview designation is clear and consistent in titles, cards, and the intro note
• Sitemap entry is properly added per the CLAUDE.md requirement

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Issues

Medium: Code snippet omits a line present in the actual example

The Rust code block in the "Inspect The Actor Code" step doesn't include the tracing_subscriber initialization present in the actual examples/rust-counter/src/main.rs. Either include it for accuracy or add a comment noting it's simplified.

Minor: API parameter documentation gap

The curl commands use crash_policy: "destroy" and runner_name_selector: "rivetkit-rust" without explanation. A brief inline comment or footnote on what these control would help users who encounter errors or want to adapt the commands.

Minor: Dev token clarification

The Authorization: Bearer dev token is appropriate for local dev, but a short note explicitly stating this is for local use only (not production) would set clearer expectations for preview users.

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Checklist

• Sitemap updated per CLAUDE.md requirement
• faRust import added to both index pages
• Preview label consistent across title, card, and intro note
• Code snippet matches actual example file (minor discrepancy)

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Overall this is a clean, well-structured docs addition. The issues above are minor and don't block merging, but the code snippet accuracy is worth a quick look before the page goes live.