Document Met Office fallback hardening

Author: Sam-Bolling

docs/research/new-publisher-source-planning/Met_Office_Exeter_Portsmouth_Demo_Site_Check_2026-05-26.md

@@ -105,4 +105,4 @@ Public CSAPI verification after deployment:
 - Exeter Airport Area system `05q0` has 9 datastreams. Latest air temperature observation: `26.73 C` at `2026-05-26T18:00:00Z`.
 - Portsmouth / Thorney Island Area system `05qg` has 9 datastreams. Latest air temperature observation: `25.54 C` at `2026-05-26T18:00:00Z`.
 
-Known follow-up: service restart logs still show the pre-existing Cairngorm datastream-list JSON parse fallback, and that fallback currently resolves only two Cairngorm datastreams for scheduled cycles. The new Exeter and Portsmouth sites are unaffected and resolved all 9 datastreams each. Treat the Cairngorm warning as a separate service-hardening item rather than part of this site addition.
+Follow-up hardening completed in commit `a39d108` (`Harden Met Office datastream fallback`). The publisher now recovers datastream IDs from paginated single-item responses when the full datastream-list JSON is malformed. After deployment, Cairngorm resolves 8 of 9 datastreams and publishes wind direction, wind speed, and wind gust again. The only remaining Cairngorm gap is `pressure_tendency`, whose single-item datastream page currently returns a server-side HTTP 500. The new Exeter and Portsmouth sites are unaffected and resolved all 9 datastreams each.