Mention triage and bulk actions

You can now triage mentions directly from the feed. Mark them as spam, dismiss them, or archive entire threads at once. Bulk-mark-as-read lets you clear the backlog in a single click, and a new triage history log shows every action taken on a thread so nothing disappears without a trace.

Triaged mentions are hidden from the default view but always accessible via the status filter if you need to revisit them.