Shard iOS RNTester E2E tests with isolated retries

Summary:
Run the RNTester iOS suite in four independent flow shards for each of Debug and Release. Each runner owns its simulator; flows remain serial within a shard.

Before every attempt, uninstall and reinstall the original app artifact, reset Keychain and app privacy permissions, and restore light appearance and portrait orientation. Retry only failed flows, continue collecting results after an exhausted flow, and retain separate reports and recordings for every attempt. Subprocess timeouts hard-kill hung commands before retry and cleanup.

Remove RNTester's whole-workflow retries and use the matrix job result to propagate any shard failure. The shared action defaults keep Templateapp unsharded with its existing state behavior.

Changelog: [Internal]

Differential Revision: D124671885

Author: Abbondanzo

.github/actions/maestro-ios/action.yml

@@ -26,6 +26,18 @@ inputs:
     required: false
     default: ''
     description: Maestro device OS name, such as iOS-26-2
+  shard-index:
+    required: false
+    default: '0'
+    description: Zero-based index of the flow shard to run
+  shard-count:
+    required: false
+    default: '1'
+    description: Number of flow shards
+  reset-app:
+    required: false
+    default: 'false'
+    description: Whether to reset the app before each flow attempt
 
 runs:
   using: composite
@@ -60,6 +72,10 @@ runs:
     - name: Run tests
       id: run-tests
       shell: bash
+      env:
+        MAESTRO_SHARD_INDEX: ${{ inputs.shard-index }}
+        MAESTRO_SHARD_COUNT: ${{ inputs.shard-count }}
+        MAESTRO_RESET_APP: ${{ inputs.reset-app }}
       run: |
         # Avoid exit from the job if one of the command returns an error.
         # Maestro can fail in case of flakyness, we have some retry logic.
@@ -74,23 +90,10 @@ runs:
           "${{ inputs.working-directory }}" \
           "${{ inputs.device-model }}" \
           "${{ inputs.device-os }}"
-    - name: Store video record
+    - name: Store Maestro reports
       if: always()
       uses: ./.github/actions/upload-artifact
       with:
-        name: e2e_ios_${{ inputs.app-id }}_report_${{ inputs.flavor }}_NewArch
-        overwrite: true
-        path: |
-          video_record_1.mov
-          video_record_2.mov
-          video_record_3.mov
-          video_record_4.mov
-          video_record_5.mov
-          report.xml
-    - name: Store Logs
-      if: failure() && steps.run-tests.outcome == 'failure'
-      uses: ./.github/actions/upload-artifact
-      with:
-        name: maestro-logs-${{ inputs.app-id }}-${{ inputs.flavor }}-NewArch
+        name: e2e_ios_${{ inputs.app-id }}_report_${{ inputs.flavor }}_NewArch_shard_${{ inputs.shard-index }}_attempt_${{ github.run_attempt }}
         overwrite: true
-        path: /tmp/MaestroLogs
+        path: maestro-reports