[codex] Fix mounted stub detection and archive linux-xr parity

[Jesssullivan]

Summary

• make the mounted lazy-hydration smoke detect actual TCFS physical stub payloads instead of failing on every legitimate .tc / .tcf filename
• archive home-canary-linux-xr-shadow-20260511T040325Z, which passes the scoped isolated-shadow linux-xr parity gate with 85 mounted symlink target checks and the Linux lifecycle companion
• update readiness, QA, evidence, and S3 posture docs to keep this as functional project-tree evidence, not production Finder or production S3 posture

Evidence

• result.env: proof=shadow-push-honey-linux-lifecycle-symlink-targets, parity_status=scoped-project-tree-parity-evidence-complete
• parity-gates.env: source_symlink_count=85, shadow_symlink_count=85, mounted_symlink_verification_status=passed
• push-storage-summary.env: 92,969 upload rows, 8,047,721,728 uploaded bytes, 405,519 chunks, 4 chunk concurrency; telemetry fields are absent because the push predates the final fresh-prefix/progress logging

Claim Boundaries

• no production Finder claim
• no broad home-directory takeover claim
• no production S3 posture claim from this debug-binary/reused-push packet
• neo/macOS M4, M8 tombstone UX, and keep-synced/pin semantics remain open

Validation

• bash scripts/test-lazy-hydration-mounted-smoke.sh
• bash scripts/test-home-canary-linux-xr-shadow.sh
• task docs:links
• task lazy:check
• git diff --check
• host proof: resumed home-canary-linux-xr-shadow against the existing shadow/prefix with honey mounted smoke and Linux lifecycle enabled