CoderWorkspacePoolMember checkCreate: trust only Coder's own 404 on the name lookup (before PR 12) #355

Summary

checkCreate in internal/controller/coderworkspacepoolmember_controller.go looks up the kwp- workspace name before the create with the plain isCoderNotFound. A 404 that Coder did not send (a proxy page, Route not found.) counts as a free name, and the member sends the create. #352 fixed the same lookup in the live CoderTemplateTest controller.

The pool member controller is dormant. Fix this before PR 12 of #153 registers it: use isCoderResourceNotFound and add tests for an HTML 404 and Route not found..

Refs #153

Generated with xum • Model: anthropic:claude-opus-5-5 • Thinking: medium