Summary

• Add downstream-shaped clean-project examples for Rust test fixtures, webhook verifier fixtures, OIDC/JWKS validation fixtures, and TLS chain validation fixtures.
• Wire cargo xtask external-adoption-smoke --path . to copy those examples into target/external-adoption-smoke/, patch dependencies for local path or published-version mode, and run each as an isolated Cargo project.
• Keep the existing installed-style CLI profile matrix unchanged and mark clean-project examples done in the active goal.

Files added/changed

• examples/external/rust-test-fixtures/
• examples/external/webhook-verifier/
• examples/external/oidc-jwks-validation/
• examples/external/tls-chain-validation/
• xtask/src/external_adoption_smoke.rs
• .uselesskey/goals/active.toml

Validation

• cargo test -p xtask external_adoption_smoke -- --nocapture
• cargo xtask external-adoption-smoke --path .
• cargo xtask external-adoption-smoke --path . --format json
• cargo clippy -p xtask --all-targets -- -D warnings
• cargo xtask docs-sync --check
• cargo xtask typos
• cargo xtask fmt
• git diff --check

Non-goals

• No v0.10.0 release prep, version bump, tag, or publish.
• No new contract packs, badges, public claims, provider compatibility claims, or production security claims.
• No adoption-regression wiring in this slice.

What this enables next

• CLI profile/bundle inspect/explain polish can now be tested against both installed-style CLI commands and clean-project adoption examples.