Distinguish cancelled PR checks from failures (#37789)

Show cancelled PR checks as Cancelled with separate counts on desktop and mobile, preserving genuine failures, pending checks, existing action permissions and older-client fallback. Carry complete provider summaries through caches and presentation; preserve Azure source completeness, folder attention priority and muted cancellation details.

Tracked in #15847 and STA-5102.

src/shared/github/pull-request-merge-state.ts

@@ -1,3 +1,4 @@
+import { getProviderChecksOutcome } from '../provider-check-summary'
 import type { CheckStatus, ProviderCheckSummary } from './pull-request-types'
 import {
   canShowGitHubPRAutoMergeControl,
@@ -41,7 +42,10 @@ export type GitHubPRMergeStateDecision = {
 
 function checksState(item: GitHubPRMergeStateInput): CheckStatus | 'none' | undefined {
   if (item.checksSummary) {
-    return item.checksSummary.state
+    const outcome = item.checksStatus
+      ? getProviderChecksOutcome(item.checksSummary, item.checksStatus)
+      : getProviderChecksOutcome(item.checksSummary)
+    return outcome === 'cancelled' ? 'failure' : outcome
   }
   return item.checksStatus
 }

src/shared/github/pull-request-types.ts

@@ -53,6 +53,7 @@ export type PRInfo = {
   state: PRState
   url: string
   checksStatus: CheckStatus
+  checksSummary?: ProviderCheckSummary
   updatedAt: string
   mergeable: PRMergeableState
   reviewDecision?: PRReviewDecision | null
@@ -105,6 +106,8 @@ export type ProviderCheckSummary = {
   total: number
   passed: number
   failed: number
+  /** Subset of failed; absent when cancellation detail is unavailable. */
+  cancelled?: number
   pending: number
   neutral: number
   /** 'pipeline' when the state is a GitLab pipeline's own verdict, so its counts are not check counts. */