fix: driver test suite & sqlite reliability

.gitignore

@@ -78,3 +78,6 @@ examples/*/public/
 !examples/multiplayer-game-patterns/public/**
 !examples/multiplayer-game-patterns-vercel/public/
 !examples/multiplayer-game-patterns-vercel/public/**
+
+# Native addon binaries
+*.node

CLAUDE.md

@@ -89,6 +89,9 @@ docker-compose up -d
 git commit -m "chore(my-pkg): foo bar"
 ```
 
+- We use Graphite for stacked PRs. Diff against the parent branch (`gt ls` to see the stack), not `main`.
+- To revert a file to the version before this branch's changes, checkout from the first child branch (below in the stack), not from `main` or the parent. Child branches contain the pre-this-branch state of files modified by branches further down the stack.
+
 **Never push to `main` unless explicitly specified by the user.**
 
 ## Dependency Management
@@ -339,6 +342,10 @@ When making changes to the engine or RivetKit, ensure the corresponding document
 - **Landing page changes**: When updating the landing page (`website/src/pages/index.astro` and its section components in `website/src/components/marketing/sections/`), update `README.md` to reflect the same headlines, features, benchmarks, and talking points where applicable.
 - **Sandbox provider changes**: When adding, removing, or modifying sandbox providers in `rivetkit-typescript/packages/rivetkit/src/sandbox/providers/`, update `website/src/content/docs/actors/sandbox.mdx` to keep provider documentation, option tables, and custom provider guidance in sync.
 
+### CLAUDE.md conventions
+
+- When adding entries to any CLAUDE.md file, keep them concise. Ideally a single bullet point or minimal bullet points. Do not write paragraphs.
+
 ### Comments
 
 - Write comments as normal, complete sentences. Avoid fragmented structures with parentheticals and dashes like `// Spawn engine (if configured) - regardless of start kind`. Instead, write `// Spawn the engine if configured`. Especially avoid dashes (hyphens are OK).

engine/CLAUDE.md

@@ -33,6 +33,10 @@ When changing a versioned VBARE schema, follow the existing migration pattern.
 - When adding fields to epoxy workflow state structs, mark them `#[serde(default)]` so Gasoline can replay older serialized state.
 - Epoxy integration tests that spin up `tests/common::TestCtx` must call `shutdown()` before returning.
 
+## Concurrent containers
+
+Never use `Mutex<HashMap<...>>` or `RwLock<HashMap<...>>`. Use `scc::HashMap` (preferred), `moka::Cache` (for TTL/bounded), or `DashMap`. Same for sets: use `scc::HashSet` instead of `Mutex<HashSet<...>>`. Note that `scc` async methods do not hold locks across `.await` points. Use `entry_async` for atomic read-then-write.
+
 ## Test snapshots
 
 Use `test-snapshot-gen` to generate and load RocksDB snapshots of the full UDB KV store for migration and integration tests. Scenarios produce per-replica RocksDB checkpoints stored under `engine/packages/test-snapshot-gen/snapshots/` (git LFS tracked). In tests, use `test_snapshot::SnapshotTestCtx::from_snapshot("scenario-name")` to boot a cluster from snapshot data. See `docs-internal/engine/TEST_SNAPSHOTS.md` for the full guide.

engine/packages/epoxy/src/ops/kv/read_value.rs

@@ -21,10 +21,7 @@ pub(crate) struct LocalValueRead {
 /// 1. **V2 value** (`EPOXY_V2/replica/{id}/kv/{key}/value`). The current write path.
 /// 2. **Legacy committed value** (`EPOXY_V1/replica/{id}/kv/{key}/committed_value`). Written by
 ///    the original EPaxos protocol. Deserialized as raw bytes with version 0 and mutable=false.
-/// 3. **Legacy v2-format value** (`EPOXY_V1/replica/{id}/kv/{key}/value`). Written during the
-///    intermediate v1-to-v2 transition where the key layout matched v2 but the subspace was
-///    still v1.
-/// 4. **Optimistic cache** (`EPOXY_V2/replica/{id}/kv/{key}/cache`). Only checked when
+/// 3. **Optimistic cache** (`EPOXY_V2/replica/{id}/kv/{key}/cache`). Only checked when
 ///    `include_cache` is true. Contains values fetched from remote replicas for the optimistic
 ///    read path.
 ///
@@ -38,24 +35,20 @@ pub(crate) async fn read_local_value(
 ) -> Result<LocalValueRead> {
 	let value_key = KvValueKey::new(key.clone());
 	let legacy_value_key = LegacyCommittedValueKey::new(key.clone());
-	let legacy_v2_value_key = KvValueKey::new(key.clone());
 	let cache_key = KvOptimisticCacheKey::new(key);
 	let subspace = keys::subspace(replica_id);
 	let legacy_subspace = keys::legacy_subspace(replica_id);
 	let packed_value_key = subspace.pack(&value_key);
 	let packed_legacy_value_key = legacy_subspace.pack(&legacy_value_key);
-	let packed_legacy_v2_value_key = legacy_subspace.pack(&legacy_v2_value_key);
 	let packed_cache_key = subspace.pack(&cache_key);
 
 	ctx.udb()?
 		.run(|tx| {
 			let packed_value_key = packed_value_key.clone();
 			let packed_legacy_value_key = packed_legacy_value_key.clone();
-			let packed_legacy_v2_value_key = packed_legacy_v2_value_key.clone();
 			let packed_cache_key = packed_cache_key.clone();
 			let value_key = value_key.clone();
 			let legacy_value_key = legacy_value_key.clone();
-			let legacy_v2_value_key = legacy_v2_value_key.clone();
 			let cache_key = cache_key.clone();
 
 			async move {
@@ -79,14 +72,6 @@ pub(crate) async fn read_local_value(
 					});
 				}
 
-				// Legacy v2-format value (v1 subspace, v2 key layout)
-				if let Some(value) = tx.get(&packed_legacy_v2_value_key, Serializable).await? {
-					return Ok(LocalValueRead {
-						value: Some(legacy_v2_value_key.deserialize(&value)?),
-						cache_value: None,
-					});
-				}
-
 				let cache_value = if include_cache {
 					tx.get(&packed_cache_key, Serializable)
 						.await?

engine/packages/pegboard-envoy/src/conn.rs

@@ -147,7 +147,7 @@ pub async fn handle_init(
 				// Read existing data
 				let (create_ts_entry, old_last_ping_ts_entry, version_entry) = tokio::try_join!(
 					tx.read_opt(&create_ts_key, Serializable),
-					tx.read_opt(&create_ts_key, Serializable),
+					tx.read_opt(&last_ping_ts_key, Serializable),
 					tx.read_opt(&version_key, Serializable),
 				)?;