#810: The update-feed handlers no longer fall back to a Joomla feed for
unset or feedless platforms. Every Serve* handler now gates positively on
its own platform constant, so npm/mcp (and any unrecognized platform)
return NotFound instead of an (empty) Joomla updates.xml. Added npm/mcp as
recognized platform constants and an IsFeedlessPlatform helper.
#811: The effective update-stream platform (RepoUpdatePlatform) is now
resolved via ResolvePlatform(cfgPlatform, metadataPlatform): an explicit
update-stream config platform wins; otherwise it derives from the repo
metadata platform (metadata.platform); only when neither is set does it
fall back to "joomla". This stops the update-stream store and the repo
metadata store from drifting and removes the "empty => joomla" fallback
at its root (services/context/repo_public_feed.go and repo.go).
No schema/migration required: UpdateStreamConfig.Platform is a plain string
column with no DB-level enum/CHECK constraint, so npm/mcp are enforced at
the application layer only.
Authored-by: Moko Consulting
Moko Consulting