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>

e2e-tests/Makefile

@@ -9,7 +9,7 @@ clean:
 	rm -fv .ci/server.yml
 	rm -fv .ci/.env.{server,dashboard,cypress,playwright}
 
-.PHONY: generate-server start-server run-test stop-server restart-server
+.PHONY: generate-server start-server run-test run-specs stop-server restart-server
 generate-server:
 	bash ./.ci/server.generate.sh
 start-server: generate-server
@@ -17,6 +17,8 @@ start-server: generate-server
 	bash ./.ci/server.prepare.sh
 run-test:
 	bash ./.ci/server.run_test.sh
+run-specs:
+	bash ./.ci/server.run_specs.sh
 stop-server: generate-server
 	bash ./.ci/server.stop.sh
 restart-server: stop-server start-server