handleBlocksLoaded reloaded the feed on every 'blocks-loaded' signal — but a
forced reload re-fetches the lists, which re-emit 'blocks-loaded', a
self-sustaining loop. Now it computes a signature of the block set and reloads
only on actual change (emit-on-change — the P5 principle). handleRelaysLoaded
only touches relay UI; hashtag prefs already dedup by signature.
Cheat-resistant regression test added. Bumped authSessionCoordinator file-size
baseline. Logged 2 pre-existing app test failures (fail at pre-session baseline)
in KNOWN_BUGS. Marks KNOWN_BUGS #2 resolved.
Co-Authored-By: Claude Opus 4.8 <[email protected]>