Auto-apply s/agent-ready-for-rerun from the PR Review Queue workflow

.github/scripts/Invoke-RerunReviewTrigger.Tests.ps1

@@ -29,7 +29,8 @@ BeforeAll {
             [string]$HeadSha = 'abc123def',
             [string]$Platform = 'android',
             [string]$PipelineRef = 'main',
-            [Int64]$RerunCommentId = 9001
+            [Int64]$RerunCommentId = 9001,
+            [Int64]$ActivityCheckpoint = 1787000000000
         )
 
         [pscustomobject]@{
@@ -38,6 +39,7 @@ BeforeAll {
             platform       = $Platform
             pipelineRef    = $PipelineRef
             rerunCommentId = $RerunCommentId
+            activityCheckpoint = $ActivityCheckpoint
         }
     }
 
@@ -243,6 +245,7 @@ Describe 'Get-RerunActions' {
         $result.Actions[0].platform | Should -Be 'ios'
         $result.Actions[0].pipelineRef | Should -Be 'main'
         $result.Actions[0].rerunCommentId | Should -Be 4242
+        $result.Actions[0].activityCheckpoint | Should -Be 1787000000000
     }
 
     It 'produces an action for a valid skip decision even without a rerun comment id' {
@@ -255,6 +258,18 @@ Describe 'Get-RerunActions' {
         $result.Actions.Count | Should -Be 1
         $result.Actions[0].decision | Should -Be 'skip'
         $result.Actions[0].rerunCommentId | Should -Be 0
+        $result.Actions[0].activityCheckpoint | Should -Be 1787000000000
+    }
+
+    It 'rejects a candidate without a scan-time activity checkpoint' {
+        $items = @(New-TestDecision -PRNumber '50' -Decision 'skip' -ExpectedHeadSha 'sha50')
+        $candidate = New-TestCandidate -PRNumber 50 -HeadSha 'sha50'
+        $candidate.activityCheckpoint = $null
+
+        $result = Get-RerunActions -Items $items -Candidates @($candidate)
+
+        $result.HadFailure | Should -BeTrue
+        $result.Actions.Count | Should -Be 0
     }
 
     It 'normalizes the pipeline ref and resolves an invalid candidate platform to android' {
@@ -333,14 +348,17 @@ Describe 'Get-RerunActions' {
         $result.Actions.Count | Should -Be 0
     }
 
-    It 'refuses to trigger when the candidate has no rerun comment id' {
+    It 'triggers when the candidate has no proven current-cycle rerun comment id' {
         $items = @(New-TestDecision -PRNumber '5' -Decision 'trigger' -ExpectedHeadSha 'x')
         $candidates = @(New-TestCandidate -PRNumber 5 -HeadSha 'x' -RerunCommentId 0)
 
         $result = Get-RerunActions -Items $items -Candidates $candidates
 
-        $result.HadFailure | Should -BeTrue
-        $result.Actions.Count | Should -Be 0
+        $result.HadFailure | Should -BeFalse
+        $result.Actions.Count | Should -Be 1
+        $result.Actions[0].prNumber | Should -Be 5
+        $result.Actions[0].decision | Should -Be 'trigger'
+        $result.Actions[0].rerunCommentId | Should -Be 0
     }
 
     It 'continues processing valid decisions after a failed one' {

.github/scripts/Invoke-RerunReviewTrigger.ps1

@@ -204,15 +204,23 @@ function Get-RerunActions {
             if ([string]$candidate.headSha -ne $expectedHeadSha) {
                 throw "PR #$prNumber decision head SHA does not match candidate head SHA."
             }
+            $activityCheckpointRaw = ConvertTo-TrimmedString $candidate.activityCheckpoint
+            if ($activityCheckpointRaw -notmatch '^[1-9]\d*$') {
+                throw "Candidate for PR #$prNumber has no valid activity checkpoint."
+            }
+            $activityCheckpoint = [Int64]$activityCheckpointRaw
 
             # Operational values come from the deterministic candidate set, not the
             # agent's emission (its platform / pipeline_ref / rerun_comment_id are advisory).
             $rerunCommentId = if ($candidate.rerunCommentId) { [Int64]$candidate.rerunCommentId } else { [Int64]0 }
             $platform = Get-PlatformFromLabels -Labels @() -Fallback ([string]$candidate.platform)
             $pipelineRef = Normalize-PipelineRef -Value ([string]$candidate.pipelineRef) -Fallback $DefaultPipelineRef
 
+            # The queue label does not prove which command created the current cycle,
+            # so source-ambiguous candidates intentionally carry no reaction target.
+            # review-trigger.yml does not need a comment to dispatch.
             if ($decision -eq 'trigger' -and $rerunCommentId -le 0) {
-                throw "Candidate for PR #$prNumber has no rerun comment id; cannot trigger."
+                Write-Host "PR #$prNumber trigger has no proven current-cycle rerun comment; dispatching without a reaction target."
             }
 
             $actions.Add([pscustomobject]@{
@@ -222,6 +230,7 @@ function Get-RerunActions {
                 pipelineRef    = $pipelineRef
                 rerunCommentId = $rerunCommentId
                 headSha        = [string]$candidate.headSha
+                activityCheckpoint = $activityCheckpoint
             })
             Write-Host "Validated PR #$prNumber decision=$decision platform=$platform pipelineRef=$pipelineRef rerunCommentId=$rerunCommentId"
         } catch {