Summary

• add cargo xtask package-surface to emit target/policy/package-surface-report.{json,md} from cargo metadata
• include package surface as an area in cargo xtask policy-report
• mark the chore(xtask): add Rust-native policy runner #176 xtask policy foundation row as landed

Validation

• cargo check -p xtask --locked
• cargo test -p xtask --locked
• cargo clippy -p xtask --all-targets --locked -- -D warnings
• cargo xtask package-surface
• cargo xtask policy-report
• cargo xtask check-file-policy --mode blocking-allowlist
• cargo fmt --all -- --check
• git diff --check

Notes

• cargo xtask policy-report exits 0 and now includes package-surface. It also reports pre-existing advisory no-panic baseline drift from Refactor plan builder into focused modules #248 moving existing panic-family sites from plan/mod.rs into plan/assembly.rs and plan/graph.rs; this PR does not regenerate the no-panic baseline.