Plugin settings pages were stacked at the bottom of Settings -> Accounts, which
put antispam's thresholds and lists under a heading about mail accounts. Each
`settings.page` now gets its own entry in the Settings nav: "Antispam filtering"
and "Mail filters".
Slot gains an optional `title` for this — the host needs a label when it gives a
slot an area of its own, and falls back to the plugin name. PluginSlot gains an
optional `plugin` filter so a host can render one plugin's bundle rather than
every binding for a slot name.
Wording: the app calls that folder Spam (i18n `nav.spam`), so the plugin's copy
now does too — "filed into Spam", "Move to Spam", "marked as spam". The IMAP
special-use stays `junk`, which is what the protocol calls it; only what the
user reads changed.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018SqJYt7jD7oUEkoY68sBZo