feat(places): name every authority a place sits in #121

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tudor merged 2 commits from feat/place-multiple-authorities into main 2026-08-21 21:56:51 +00:00

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Author	SHA1	Message	Date
TudorandClaude Opus 5	bb2f7a5841	fix(places): address review, and merge places GIAS spells more than one way ... Two findings from review on #121, plus a third the review prompted. The cap at three authorities silently dropped the fourth in exactly the case where the information matters most — a genuinely fragmented place — and contradicted the stated goal of naming every authority a place sits in. It is gone. The share rule was always the real limit and already bounds the list at ten. Measured against the live corpus, one town would have been truncated today: LONDON, split evenly between Hackney, Lambeth, Westminster and Lewisham. parent_authority used mode() while authorities used value_counts(), and on an exact tie pandas does not guarantee the two pick the same name, so the 301 could have pointed somewhere other than the authority named first on the page. The parent is now derived from authorities[0]: one computation, one answer. It also inherits the sentinel filter, so a place can no longer redirect to /schools/authority/does-not-apply. Chasing the truncation case surfaced a worse bug. Places were grouped by raw town value, but the registry is keyed by slug, and GIAS spells the same place several ways. Five town slugs come from more than one spelling: "London" (1,819 schools) and "LONDON" (12) both slugify to `london`, so the later group simply overwrote the earlier one — /schools/london could have shown twelve schools, silently, depending on row order. Weston-super-Mare was split 14/19 across two spellings and Newcastle-under-Lyme across three. Grouping is now by slug, and the display name is the most common spelling. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_015mWQnpye9F299NVRCCSRvj	2026-08-21 22:42:18 +01:00
TudorandClaude Opus 5	1cb5314c53	feat(places): name every authority a place sits in ... SW19 is mostly Merton but partly Wandsworth, and the page said only Merton. The cause was one field doing two jobs: _parent_authority takes the modal authority, which is right for a 301 target and wrong as a statement about where a place is. This is not a corner case. A quarter of viable outcodes (425 of 1,760) and a third of viable towns (263 of 783) cross an authority boundary — Bedford the town spans Bedford and Central Bedfordshire. Place now carries `authorities`, every authority holding at least a tenth of the schools and at least two of them, largest first. parent_authority stays single and unchanged, because a redirect still needs one target. The share threshold exists because GIAS carries postcode errors: EN6 lists two Shropshire schools among fourteen in Hertfordshire, and a bare "any authority present" rule would print those as though they were real. A place too small or too fragmented to clear the threshold still names its largest, so the page never goes silent about where it is. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_015mWQnpye9F299NVRCCSRvj	2026-08-21 22:40:58 +01:00