Headless OAuth setup; agent sharing redesign with publish-as-template

New features

• Fleet tools now include Salesforce OAuth provider setup for self-hosted users, so you can configure the provider end to end.

• Agent sharing is redesigned around two choices, who can use and who can edit an agent, plus a Publish as template option that lets others fork their own editable copy.

• Fleet agents now post a notification to the originating thread, such as Slack, when they pause at a human-in-the-loop interrupt, with a link back to the agent chat.

• You can now complete Fleet integration OAuth through your own callback URL, so headless setups can finish authentication without the LangSmith UI.

• Agent cards now show the agent owner.

• New first-party templates, Brand Copywriter and Applicant Screening, are available in the gallery.

Fixes

• Switching threads in the agent chat now clears the previous thread immediately and shows a loading state instead of stale messages.

• The skills list now degrades gracefully when one skill fails to load, so the remaining skills still appear.