Trigger.dev v4.7.3 adds session permissions and chat-session tags

Trigger.dev v4.7.3 now requires session-write and task-trigger permissions to create or resume sessions through POST /api/v1/sessions. Scoped API keys and public tokens need write:sessions or access to the target session, plus permission to trigger its task. Teams using those credentials for chat sessions should check that they have the required task-trigger access. The chat.createStartSessionAction, chat.headStart, and chat.startHeadStart helpers now accept tags for labeling sessions, which can then be filtered on the Sessions page. The triggerConfig.tags option still applies to session runs, not the session itself. Server changes are included in the v4.7.3 Docker image and are live on Trigger.dev Cloud. Self-hosted users can update their Docker image to v4.7.3.