Keep RC update checks off perf prereleases

Co-authored-by: Orca <help@stably.ai>

src/main/updater-prerelease-feed.test.ts

@@ -187,6 +187,29 @@ describe('fetchNewerReleaseTag', () => {
     expect(await fetchNewerReleaseTag('1.3.19-rc.6')).toBe('v1.3.20-rc.1')
   })
 
+  it('ignores perf-tagged prereleases for regular RC checks', async () => {
+    respondWithAtom(['v1.4.121-rc.6.perf', 'v1.4.121-rc.6', 'v1.4.121-rc.5'])
+
+    const { fetchNewerReleaseTag } = await import('./updater-prerelease-feed')
+
+    expect(await fetchNewerReleaseTag('1.4.121-rc.5', { includePrerelease: true })).toBe(
+      'v1.4.121-rc.6'
+    )
+  })
+
+  it('reports no RC update when only perf-tagged prereleases are newer', async () => {
+    respondWithAtom(['v1.4.121-rc.6.perf', 'v1.4.121-rc.5'])
+
+    const { fetchNewerReleaseTagsWithReadiness } = await import('./updater-prerelease-feed')
+
+    await expect(
+      fetchNewerReleaseTagsWithReadiness('1.4.121-rc.5', 1, { includePrerelease: true })
+    ).resolves.toEqual({
+      tags: [],
+      state: 'no-newer'
+    })
+  })
+
   it('picks the semver-newest perf-tagged prerelease', async () => {
     respondWithAtom([
       'v1.4.121-rc.6.perf',

src/main/updater-prerelease-feed.ts

@@ -203,11 +203,13 @@ export async function fetchNewerReleaseTagsWithReadiness(
     return { tags: [], state: 'unavailable' }
   }
 
+  // Why: perf builds are explicit opt-in; regular prerelease checks should
+  // stay on the main RC/stable series even though perf tags are semver-newer.
   const candidates =
     options.releaseFilter === 'perf'
       ? tags.filter(({ tag }) => isPerfPrereleaseTag(tag))
       : includePrerelease
-        ? tags
+        ? tags.filter(({ tag }) => !isPerfPrereleaseTag(tag))
         : tags.filter(({ version }) => !isPrereleaseVersion(version))
   const newestNewerIndex = candidates.findIndex(
     ({ version }) => compareVersions(version, currentVersion) > 0