* sftp: match permission paths on path-component boundaries
Permission checks compared paths with raw string prefixes, so a
permission entry for /tenants/alice also matched sibling paths such as
/tenants/alice-archive, letting a scoped user read and overwrite
another tenant's files. The home directory containment check had the
same flaw. Route both through pathWithin, which cleans the paths and
requires exact equality or a separator-delimited descendant.
* sftp: clean permission path into a local when ranking matches
fix: don't mangle filer paths with the OS separator on Windows
filepath.Dir/Join use the platform separator, so on Windows they rewrite
a forward-slash filer path like /buckets/x into \buckets\x. The mangled
value then goes into a filer RPC and operates on the wrong key, so the
op silently targets nothing.
The admin file browser hit this in New Folder (the entry landed under
\buckets\my-bucket and never showed up under /buckets/my-bucket), and
the same way in delete, view and properties. MQ topic retention and
consumer-offset listing, and the SFTP home dir plus create-permission
parent lookup, had the same bug.
Switch all of these to the path package, which always uses "/".
Chris Lu