The compare page's phase tabs put all-through schools (which carry KS4
data) on the secondary tab, so comparing an all-through school with a
pure primary splits them across tabs and only the active tab renders its
link. The test picked the first two 'primary' search hits without
guaranteeing same phase, so it flaked whenever a search returned an
all-through school first (e.g. URN 137306). Now selects two pure-Primary
URNs via the API — deterministic and data-invariant.
Verified against staging: was a 15.6s timeout, now passes in ~1.8s.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0146VHeLAWjDVE2B5uU67jCB
