fix(memory): align evicted upstream generations

src/main/git/source-control/effective-upstream-status-cache.ts

@@ -38,6 +38,10 @@ export function getEffectiveUpstreamStatusGenerationCountForTests(): number {
   return effectiveUpstreamStatusWriteGeneration.size
 }
 
+export function getEffectiveUpstreamStatusWriteGeneration(cacheKey: string): number {
+  return effectiveUpstreamStatusWriteGeneration.get(cacheKey) ?? evictedWriteGeneration
+}
+
 export function getEffectiveUpstreamStatusCacheKey(
   worktreePath: string,
   branchName: string,

src/main/git/source-control/effective-upstream-status-probe.ts

@@ -11,7 +11,7 @@ import { gitExecFileAsync } from '../runner'
 import {
   MAX_EFFECTIVE_UPSTREAM_NEGATIVE_CACHE_ENTRIES,
   effectiveUpstreamStatusInFlight,
-  effectiveUpstreamStatusWriteGeneration,
+  getEffectiveUpstreamStatusWriteGeneration,
   readCachedEffectiveUpstreamStatus,
   rememberEffectiveUpstreamStatus,
   trimEffectiveUpstreamStatusGeneration
@@ -46,7 +46,7 @@ export async function readOrProbeEffectiveUpstreamStatus(
   }
 
   // Why: overlapping refreshes at startup — coalesce the upstream probe so a stable missing ref fails once.
-  const writeGeneration = effectiveUpstreamStatusWriteGeneration.get(cacheKey) ?? 0
+  const writeGeneration = getEffectiveUpstreamStatusWriteGeneration(cacheKey)
   const probe = probeOrRevalidateEffectiveUpstreamStatus(
     cacheKey,
     worktreePath,

src/main/git/status-upstream-negative-cache.test.ts

@@ -45,6 +45,11 @@ import {
   getEffectiveUpstreamStatusGenerationCountForTests,
   getStatus
 } from './status'
+import {
+  getEffectiveUpstreamStatusWriteGeneration,
+  readCachedEffectiveUpstreamStatus,
+  rememberEffectiveUpstreamStatus
+} from './source-control/effective-upstream-status-cache'
 
 describe('local upstream negative cache', () => {
   beforeEach(() => {
@@ -405,4 +410,23 @@ describe('local upstream negative cache', () => {
     expect(getEffectiveUpstreamStatusCacheCountForTests()).toBe(0)
     expect(getEffectiveUpstreamStatusGenerationCountForTests()).toBe(512)
   })
+
+  it('continues caching new negatives after generation eviction', () => {
+    const now = Date.now()
+    for (let index = 0; index < 513; index += 1) {
+      rememberEffectiveUpstreamStatus(
+        `positive-${index}`,
+        { hasUpstream: true, ahead: 0, behind: 1 },
+        now,
+        true,
+        0
+      )
+    }
+    const cacheKey = 'new-negative'
+    const writeGeneration = getEffectiveUpstreamStatusWriteGeneration(cacheKey)
+    const status = { hasUpstream: false, ahead: 0, behind: 0 }
+    rememberEffectiveUpstreamStatus(cacheKey, status, now, true, writeGeneration)
+
+    expect(readCachedEffectiveUpstreamStatus(cacheKey, now)).toEqual(status)
+  })
 })