Sort dev builds by timestamp instead of semver

Dev build base versions can move backwards when a branch is cut before
the latest main build. Their embedded timestamp is the authoritative
"newest" signal for the picker. For dedicated release repos, compare
publishedAt timestamps before falling back to semver comparison.

src/shared/release-channel.test.ts

@@ -324,4 +324,24 @@ describe('release channel', () => {
       '1.4.160-adhoc.20260728090000'
     ])
   })
+
+  it('sorts dev builds by their cut time across different base versions', () => {
+    const build = (version: string): ReleaseBuild => ({
+      tag: `v${version}`,
+      version,
+      channel: 'adhoc',
+      name: null,
+      publishedAt: null,
+      releaseUrl: `https://github.com/stablyai/orca-adhoc/releases/tag/v${version}`,
+      installerUrl: null
+    })
+    const sorted = sortReleaseBuildsNewestFirst([
+      build('1.4.207-adhoc.20260919025813'),
+      build('1.4.206-adhoc.20260919173504')
+    ])
+    expect(sorted.map((entry) => entry.version)).toEqual([
+      '1.4.206-adhoc.20260919173504',
+      '1.4.207-adhoc.20260919025813'
+    ])
+  })
 })

src/shared/release-channel.ts

@@ -319,5 +319,28 @@ export type ReleaseBuild = {
 
 /** Newest first, so the picker's first row is always the channel's current tip. */
 export function sortReleaseBuildsNewestFirst(builds: ReleaseBuild[]): ReleaseBuild[] {
-  return [...builds].sort((left, right) => compareAppVersions(right.version, left.version))
+  return [...builds].sort((left, right) => {
+    // Dev build base versions can move backwards when a branch was cut before
+    // the latest main build. Their stamped build time, not semver, is the
+    // meaningful "newest" signal for the picker.
+    const leftStamp = parseDevBuildStamp(left.version)?.getTime() ?? null
+    const rightStamp = parseDevBuildStamp(right.version)?.getTime() ?? null
+    if (leftStamp !== null && rightStamp !== null && leftStamp !== rightStamp) {
+      return rightStamp - leftStamp
+    }
+
+    if (hasDedicatedReleaseRepo(left.channel) && hasDedicatedReleaseRepo(right.channel)) {
+      const leftPublished = left.publishedAt ? Date.parse(left.publishedAt) : Number.NaN
+      const rightPublished = right.publishedAt ? Date.parse(right.publishedAt) : Number.NaN
+      if (
+        Number.isFinite(leftPublished) &&
+        Number.isFinite(rightPublished) &&
+        leftPublished !== rightPublished
+      ) {
+        return rightPublished - leftPublished
+      }
+    }
+
+    return compareAppVersions(right.version, left.version)
+  })
 }