* core, ui: plan per-server roles for self-hosted servers
* core: add per-server roles field to UserServer
* core: add nullable role columns to protocol_servers
* core: persist per-server roles
* core: validate server coverage using per-server roles
* test: cover per-server roles resolution and coverage
* multiplatform: per-server role toggles for self-hosted servers
* ios: per-server role toggles for self-hosted servers
* core: per-server role overrides with per-role defaults
* test: cover three-state per-server role resolution
* fix: derive Eq for ServerRolesOverride
* multiplatform: three-state role dropdowns on saved servers
* ios: three-state role pickers on saved servers
* test: per-server roles independent across two servers
* test: enable names role in name-resolution tests
* style: trim comments in per-server roles code
* chore: rename server_roles migration to 20260716 (last)
* core: per-server roles override operator roles, inherit when unset
* multiplatform: per-server role default inherits from operator
* ios: per-server role default inherits from operator
* refactor(servers): tidy per-server roles per review
- dedup no-operator default into ServerRoles.noOperatorDefault (Kotlin/Swift)
- iOS: move roles-section control flow to the call site via a named gate,
and parse the server address once instead of up to three times
- Kotlin: collapse redundant derivedState; revert defaultOn->default rename
for cross-platform parity
- drop unused Hashable conformance on Swift ServerRoles
- add agentServerCfgs test for names inheritance from an operator
- remove no-op enableNamesRole calls from dormant DirectoryTests
- fix ChatClient import ordering
* chore(migration): date server_roles migration 20260720
* only show roles when server is enabled, move section above QR code
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Co-authored-by: Evgeny Poberezkin <evgeny@poberezkin.com>
