update: elastos update deletes installed Home/System on a source-installed Home when its capsules map changes #270

Part of #89.

Found 6 Oct while fixing #259's journey. evict_changed_capsule_cache (develop update.rs:456, called at :1644) runs remove_dir_all(capsules/<name>) for every entry whose CID changed in components.json's capsules map, including the Home and System it has just installed.
Released Homes are not affected: real releases publish capsules: {} (release-platform-input.py:899, :417). A source-installed Home has a non-empty map, so elastos update there would delete its installed Home and System.
Done means: eviction never removes a capsule the same update just installed; a test runs a source-Home update with a changed capsules map and Home still opens. Owner: operator lane.

Browser plan reconciliation — 2026-10-08

#288's source-home update/repair cases consume this issue's Home/System preservation result. The Browser role closure remains #217's producer work, so this defect is a separate update gate. Preserve admitted capsule trees and rooted user/profile state while activating the exact compatible candidate through #108; original Done means remains unchanged.