feat: add intake queue commands

[ericmaster]

Disclaimer

This was created by my AI Agent, it was supposed to be an intake itlsef for later PR but it got carried away 😅. Anyway, the PR is created, if rejected no hard feelings.

Summary

Adds intake sub-command to planecli for managing project intake queues.

The Plane SDK does not expose intake endpoints, so these commands use direct HTTP calls.

Commands

Command	Description
intake ls -p PROJECT	List items in a project's intake queue
intake create "title" -p PROJECT [-d desc] [-P priority]	Create a new intake item
intake accept ID -p PROJECT	Accept/triage an intake item (converts to work item)
intake decline ID -p PROJECT	Decline an intake item
intake delete ID -p PROJECT	Delete an intake item
intake enabled PROJECT	Check if intake_view is enabled for a project

All commands require -p/--project (fuzzy name/identifier/UUID resolved via resolve_project_async). The ls and create commands auto-check intake_view and warn if intake is disabled.

JSON output (--json) goes to stdout for scripting; tables go to stderr (consistent with existing commands).

Testing

Verified end-to-end against a self-hosted Plane instance:

• intake enabled PROJ1_INTAKE_ENABLED → correctly reports true
• intake enabled PROJ2_NO_INTAKE → correctly reports false
• intake create → creates item with correct name, description_html, priority
• intake ls → lists items with flattened issue_detail fields
• intake delete → deletes by issue_detail UUID (204 response)
• intake accept / intake decline → PATCH status 1 / -1

Notes

• Delete uses the issue_detail.id (the actual issue UUID), not the intake wrapper id — this is a known gotcha with the Plane intake API.
• Description is automatically wrapped in <p>…</p> for the required description_html field.
• Priority defaults to none; valid values: none, low, medium, high, urgent.