Add deployed Playwright workflow to master

[ghoshArnab]

Summary

• Add a manually dispatched Chromium workflow for the MediaCo portal and embedded tests against an approved deployed origin.
• Restrict targets to canonical HTTPS origins in the playwright-test environment's PLAYWRIGHT_ALLOWED_ORIGINS variable.
• Serialize runs per target, check app reachability, accept TLS errors, and upload the Playwright report.
• Use unique emails for persistent test records.

Setup

Configure the playwright-test GitHub environment with a comma-separated PLAYWRIGHT_ALLOWED_ORIGINS variable and any required reviewers.

Validation

Formatting, diagnostics, and discovery of all five selected tests passed. The live suite was not run because an approved deployed target was not available.