chore: rivetkit to rust

[NathanFlurry]

Description

Please include a summary of the changes and the related issue. Please also include relevant motivation and context.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

Please describe the tests that you ran to verify your changes.

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

[NathanFlurry]

Warning

This pull request is not mergeable via GitHub because a downstack PR is open. Once all requirements are satisfied, merge this PR as a stack on Graphite.
Learn more

• chore: move rivetkit to task model #4680
• chore: rivetkit to rust #4679 👈 (View in Graphite)
• feat(rivetkit): sqlite vfs v2 #4673
• chore: rename sandbox -> kitchen sink #4671 : 1 other dependent PR (#4672 )
• chore: configure TLS trust roots for rustls clients #4667
• fix(rivetkit): update config to match envoys & remove manager references #4663
• chore(publish): pin docker base image refs #4652
• chore(engine): publish engine bases in ci #4649 : 2 other dependent PRs (#4650 , #4666 )
• chore: lockfile lefthook #4647
• fix(rivetkit): surface native sqlite kv errors to callers #4645
• fix(rivetkit): prevent sleep races during disconnect and db work #4644
• fix(rivetkit): isolate engine envoys and propagate startup failures #4643
• test(rivetkit): remove wasm sqlite-only fixtures and coverage #4642
• chore(sqlite-vfs): remove wasm sqlite packages and workspace wiring #4641
• chore(rivetkit): remove wasm sqlite runtime #4614
• fix(sqlite-native): restore native startup kv preload #4639
• fix(sqlite-native): delete metadata before chunk range #4638
• fix(sqlite-native): keep truncate cache coherent #4637
• fix(sqlite-vfs): use delete range for truncate cleanup #4636
• fix(sqlite-native): restore kv error hook #4635
• perf(sqlite-native): avoid cloning cached read chunks #4634
• perf(sqlite-native): gate kv operation labels #4633
• perf(sqlite-native): reuse read cache for partial writes #4632
• perf(sqlite-native): remove delete file existence probe #4631
• fix(sqlite-native): gate native read cache behind env var #4630
• fix(pegboard): isolate runner config dc lookup failures #4625 : 1 other dependent PR (#4626 )
• docs(pegboard): note runner config upsert split write risk #4624
• fix(pegboard): unpack global runner config keys correctly #4623
• fix(pegboard-gateway): enforce tunnel message state #4622
• fix(pegboard-runner): clear terminal tunnel routes #4621
• fix(pegboard): skip protocol version keys in runner pool backfill #4620
• fix(pegboard): create missing normal runner configs #4619
• fix(epoxy): reuse cached optimistic value #4618
• main

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[railway-app]

🚅 Deployed to the rivet-pr-4679 environment in rivet-frontend

Service	Status	Web	Updated (UTC)
website	😴 Sleeping (View Logs)	Web	Apr 21, 2026 at 1:20 am
kitchen-sink	❌ Build Failed (View Logs)	Web	Apr 20, 2026 at 12:08 am
frontend-cloud	❌ Build Failed (View Logs)	Web	Apr 19, 2026 at 7:39 pm
frontend-inspector	❌ Build Failed (View Logs)	Web	Apr 19, 2026 at 7:39 pm
ladle	❌ Build Failed (View Logs)	Web	Apr 18, 2026 at 9:39 pm
mcp-hub	✅ Success (View Logs)	Web	Apr 18, 2026 at 9:38 pm

[claude]

PR 4679 Review - rivetkit to rust migration (draft, ~47K additions)

BLOCKING ISSUES

1. Mutex-HashMap Violations
   CLAUDE.md requires scc::HashMap, never Mutex-HashMap. Six violations found:

• rivetkit-rust/packages/rivetkit-core/src/actor/queue.rs: completion_waiters
• rivetkit-typescript/packages/rivetkit-napi/src/bridge_actor.rs:22-30: ResponseMap, WsSenderMap, SqliteStartupMap, SqliteSchemaVersionMap
  All should use scc::HashMap to avoid lock contention.

2. destroy_actor and stop_actor Send Identical Intent
   engine/sdks/rust/envoy-client/src/handle.rs:71-87: Both send ActorIntentStop. If destroy_actor should permanently remove an actor, this is a bug. If intentional, consolidate or document equivalence.

3. Placeholder Sandbox Documentation
   website/src/content/docs/actors/sandbox.mdx contains only a placeholder. Before landing: complete docs, remove from sitemap, or redirect to working alternative.

MINOR ISSUES

• Queue payloads support only v4 while actor state supports v3+v4. Add comment confirming intentional.
• counter.rs: initialize_schema is a no-op (SQLite unfinished). Mark WIP or gate behind feature flag.

STRENGTHS

• scc::HashMap used correctly in RegistryDispatcher (active_instances, stopping_instances)
• moka::Cache for SQLite page cache
• Structured tracing throughout, no bare println!/eprintln!
• Versioned persistence pattern (encode_with_embedded_version / decode_with_embedded_version) cleanly applied
• Real-process NAPI integration tests, no module-level mocking
• Two-phase factory pattern and Arc-ActorContext ownership model are clean