Roundcube auto-detects the delimiter from the IMAP server via LIST
command. Remove hardcoded fallback values and let Roundcube handle
detection when no delimiter is explicitly configured.
When switching identities, the managesieve plugin still connected to
the default sieve server. Hook into managesieve_connect to redirect
the sieve connection to the remote account's server.
Adds sieve_host, sieve_port and sieve_auth columns to the database,
a Sieve section to the identity settings form, preconfig support for
sieve_host, and localized labels for all 7 languages.
Extract business logic into dedicated classes under lib/:
- IdentSwitchForm: form building, validation, and persistence
- IdentSwitchSwitcher: account switching, SMTP config, special folders
- IdentSwitchPreconfig: domain-based preconfiguration
The main plugin class remains the orchestrator, registering hooks
and delegating to the appropriate handler. Constants changed from
private to public to allow cross-class access.
