In-container Playwright runs were flaky: the chromium renderer crashed
mid-build ("Target crashed") on the 64M /dev/shm, and login intermittently
hung. Added `--disable-dev-shm-usage` + `--no-sandbox` launch args, a
4-attempt login retry loop (domcontentloaded + explicit selector wait),
and an `ELM_GUID` env override so a per-UPRN assessment can be targeted
without editing the module. Tooling only — no calculator impact.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>