Copilot readiness controls

Fix oversharing before Copilot finds it, then roll Copilot out with Purview guardrails.

ID	Control	Priority	Effort
CR01	Find the overshared sites before Copilot does	Highest	2 h
CR02	Hide the riskiest sites from Copilot while you fix them (Restricted Content Discovery)	Highest	1 h
CR03	Make 'Specific people, view' the default sharing link and put an expiry on Anyone links	High	1 h
CR04	Remove 'Everyone except external users' from sensitive sites and hide it in the people picker	High	2 h + site owner time
CR05	Confirm Copilot interactions are audited and searchable	High	30 min

These are the free Top 5. The M365 Copilot Readiness Kit has all 24 controls, with the Jira import, Excel plan and read-only script.