Wire xct2cli XML fixtures into tests and anonymize them

• Status: Todo
• Kind: Chore
• Authors: jp
• Date: 2026-08-21
• Label: package=xct2cli
• Label: type=task

crates/contrib/xct2cli/tests/fixtures/sample-toc.xml and time-sample.xml have no test consumer; the parser tests use inline XML. The files also retain a device name, device UUID, username-bearing absolute path, and process IDs while the README calls the exported fixtures safe to keep.

Acceptance criteria:

• Add tests that parse both checked-in fixture files through the production entry points, or delete the files if the inline cases fully replace them.
• Assert the meaningful TOC and time-sample business outcomes exactly.
• Replace device names, UUIDs, user paths, process IDs, and addresses with stable synthetic values unless a raw value is needed by the parser case.
• Clarify the README: exported XML omits the trace bundle's environment secrets but still requires anonymization before commit.