This is a comment left during a code review.
Path: lib/session-affinity.ts
Line: 127-154

Comment:
**version-space contamination: integer versions permanently lose to timestamp fallback writes**

`writeVersion` is used as two incompatible things:
- an integer counter (`sessionAffinityVersion = 1, 2, 3 …`) assigned in the `onResponseId` callback
- a unix-millisecond timestamp (`Date.now() ≈ 1_700_000_000_000`) assigned by the `remember()` fallback, which calls `rememberWithVersion(key, idx, now, now)`

the stale guard `entry.writeVersion > writeVersion` (lines 143-145 and 83-85) works correctly when both sides use the same version space — but once a timestamp-versioned entry is stored, every future integer-versioned write is rejected because `1.7e12 >> 3`.

the contamination path exists today in `index.ts`:
```typescript
if (!responseContinuationEnabled || (!isStreaming && !storedResponseIdForSuccess)) {
    sessionAffinityStore?.remember(sessionAffinityKey, ...);  // writeVersion = Date.now()
}
```
this fires for **non-streaming requests where `responseContinuationEnabled=true` but `onResponseId` never fires** (`storedResponseIdForSuccess` stays `false`). after that one call, all subsequent `rememberWithVersion(…, sessionAffinityVersion)` writes for that session are silently rejected, freezing the preferred account and response-id indefinitely.

fix — thread the per-request integer version into the fallback success path in `index.ts`:
```typescript
if (!responseContinuationEnabled || (!isStreaming && !storedResponseIdForSuccess)) {
    sessionAffinityStore?.rememberWithVersion(
        sessionAffinityKey,
        successAccountForResponse.index,
        Date.now(),
        sessionAffinityVersion,  // ← same integer version used in onResponseId
    );
}
```

How can I resolve this? If you propose a fix, please make it concise.

---

This is a comment left during a code review.
Path: index.ts
Line: 317-319

Comment:
**`sessionAffinityWriteVersion` declared outside the plugin closure — document the intent**

lines 317-319 have zero indentation while every other per-invocation `let` immediately above and below (310-316, 320) is indented one tab inside `OpenAIOAuthPlugin`. `sessionAffinityWriteVersion` therefore lives at module scope, consistent with the pre-existing `sessionAffinityStore`.

being at module scope is actually _correct_ here — a reset to `0` on each plugin reload would cause stale writes from pre-reload requests to overwrite post-reload ones. but the mismatched indentation makes the intent opaque and risks a future author accidentally pulling it inside the closure. consider adding a short comment:
```suggestion
// module-scope: shared across plugin reloads so the counter is strictly
// monotonic for the lifetime of the process — do not move inside the closure.
let sessionAffinityWriteVersion = 0;
```

How can I resolve this? If you propose a fix, please make it concise.

---

This is a comment left during a code review.
Path: test/session-affinity.test.ts
Line: 147-159

Comment:
**missing vitest coverage: timestamp-version contamination from `remember()` fallback**

the new regression test correctly covers integer-vs-integer stale rejection. there is no test for the mixed version-space scenario where `remember()` (timestamp version) fires for a session that already has or will receive integer-versioned writes.

suggested additional case:
```typescript
it('remember() timestamp version does not block subsequent rememberWithVersion() integer writes', () => {
    const store = new SessionAffinityStore({ ttlMs: 10_000, maxEntries: 4 });
    // integer-versioned write from onResponseId
    store.rememberWithVersion('session-a', 1, 1_000, 1);
    store.updateLastResponseId('session-a', 'resp_first', 2_000, 1);
    // simulate fallback remember() — note: in prod writeVersion = Date.now() ≈ 1.7e12
    // use a large value to reproduce the contamination
    store.rememberWithVersion('session-a', 1, 3_000, 1_700_000_000_000);
    // next integer-versioned write must NOT be rejected
    store.rememberWithVersion('session-a', 2, 4_000, 2);
    store.updateLastResponseId('session-a', 'resp_second', 5_000, 2);
    expect(store.getPreferredAccountIndex('session-a', 5_500)).toBe(2);
    expect(store.getLastResponseId('session-a', 5_500)).toBe('resp_second');
});
```
this test will fail with the current implementation, confirming the contamination bug.

How can I resolve this? If you propose a fix, please make it concise.