buildTranscriptPage wrote the normalized '_unattributed' sentinel into the page FRONTMATTER but stored the raw resolved remote ('' when unresolvable) on the page object. The policy filter fast-paths !p.git_remote, so under --include-unattributed an explicit '_unattributed → deny' (or read-only) policy never applied to exactly the pages it names — they ingested unpoliced. The stored value now matches the frontmatter.
Regression test (fails on v1.68.3.0): seeds the REAL bin/gstack-gbrain-repo-policy store with '_unattributed → deny' through its own set verb, ingests an unresolvable-remote session with --include-unattributed, and asserts nothing reaches gbrain — pre-fix the '' remote bypassed the filter and the import ran. A fake echoing tiers would pass on both sides of the fix; the real helper prints 'none' for unknown keys, so only a genuinely applied deny distinguishes the two.
Fixes#2353