Repair-SharePointNames

Processes only items flagged as INVALID_SHAREPOINT_NAME in a consolidated
migration-warnings.csv generated from SPMT assessment scan logs. It never
scans the filesystem on its own, so only items SPMT actually flagged are
touched.

Temp/system files (Office lock files, desktop.ini, InDesign lock files) are
moved to a quarantine folder, preserving their relative folder structure,
rather than deleted. All other flagged items are renamed, replacing
characters SharePoint Online does not allow (" * : < > ? / \ |) with '-'.

Entries are processed deepest-path-first so a flagged folder is never
renamed before the flagged items inside it are handled. If a cleaned name
collides with an existing item, a numeric suffix is appended, e.g.
"report (2).txt". Quarantine moves never overwrite: an existing quarantined
file at the same relative path also gets a numeric suffix.