* fix(privacy): redact complete shared labels containing paths

Whitespace was treated as the end of a filesystem path, allowing names
such as /a b to export the remaining b after the redaction marker.
Redact the complete label before URL filtering and preserve ordinary
namespaced model IDs and measured aggregate amounts.

Add snapshot-level regression cases for Unix, quoted, file-URL, tilde and
Windows paths with spaces. The six cases fail before the fix and pass
afterward, alongside the existing native image/text export checks.

Documentation impact: update the Share usage guide and Unreleased
security changelog. TODO is unaffected because no parity item is
completed. Configuration, translations and CLI contracts are unchanged.

* fix(privacy): preserve label text around web URLs

Apply HTTP(S) URL filtering before the filesystem-path check so URL
slashes cannot hide the complete shared model label. Keep file URLs
subject to whole-label redaction and cover labels mixing web URLs and
actual paths.

The HTTP and HTTPS regression cases failed before this change. All 33
ShareUsage tests now pass, including the six path-with-spaces cases.
Documentation impact: existing usage and security changelog descriptions
remain accurate; no configuration, translation or parity TODO changes.