Mm 67896 manual cherry pick onto release 10.11 (#35989)

* improves time limit checks

* consistently check for presence of patch fields

* fix variable shadowing in test

* allow idempotent pinning operations with time limit expired

* new utility function for post limit time check

* fix style issue

* Add missing E2E CI files and delivery-platform migration for release-10.11

- Add calculate-playwright-results and calculate-cypress-results GitHub Actions
  (referenced by e2e-tests-playwright-template.yml and e2e-tests-cypress-template.yml
  but never backported to release-10.11)
- Add e2e-tests/playwright/merge.config.mjs (required by merge-reports step)
- Add run-specs Makefile target and server.run_specs.sh (required by run-failed-tests job)
- Fix merge-shard-results step: pin @playwright/test version and add fallback
  for when no blob reports exist (json reporter output used directly)
- Remove pull_request trigger from e2e-tests-ci.yml (delivery-platform migration)
- Remove dead e2e-fulltests-ci.yml and e2e-tests-ci-template.yml

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Mattermost Build <build@mattermost.com>
Co-authored-by: yasserfaraazkhan <attitude3cena.yf@gmail.com>
Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

.github/actions/calculate-playwright-results/package.json

@@ -0,0 +1,27 @@
+{
+  "name": "calculate-playwright-results",
+  "private": true,
+  "version": "0.1.0",
+  "main": "dist/index.js",
+  "scripts": {
+    "build": "tsup",
+    "prettier": "npx prettier --write \"src/**/*.ts\"",
+    "local-action": "local-action . src/main.ts .env",
+    "test": "jest --verbose",
+    "test:watch": "jest --watch --verbose",
+    "test:silent": "jest --silent",
+    "tsc": "tsc -b"
+  },
+  "dependencies": {
+    "@actions/core": "3.0.0"
+  },
+  "devDependencies": {
+    "@github/local-action": "7.0.0",
+    "@types/jest": "30.0.0",
+    "@types/node": "25.2.0",
+    "jest": "30.2.0",
+    "ts-jest": "29.4.6",
+    "tsup": "8.5.1",
+    "typescript": "5.9.3"
+  }
+}