checkForUpdates() reads an optional "envs" map from the update manifest and,
when it holds an entry for this build's ENV_NAME, offers that version instead
of the global latest_version. Boards with no entry are unaffected.
This lets the OTA server hold a specific product at an older release while the
rest of the fleet advances, with no per-board build flags. The resolved value
is republished as latest_version so the Home Assistant update entity compares
against it, and the map itself is dropped from the retained state topic to
keep it small.
Backward compatible both ways: old firmware ignores "envs", and a manifest
without "envs" behaves exactly as before.
OTA_JSON_URL is also guarded with #ifndef so a build environment can point the
update check at another OTA server. It was defined unconditionally, so a -D
build flag could not retarget it (the header definition always won). This is
needed to exercise the check against a test manifest, and is useful for
self-hosted OTA servers. No behaviour change without an override.
Co-authored-by: Claude Opus 5 <noreply@anthropic.com>
