test: add executable SQL 0.2 conformance kit

[bobisme]

Implements bn-1ra4 against the reviewed SQL 0.2 contract.

• exact typed value, metadata, limit, lifecycle, and error fixtures
• reproducible 0.1/0.2 components with frozen 0.1 compatibility
• production Sigil store, lock, generated-stub, require, and real Lua lifting path for both nominal versions
• executable driver malformed/boundary vectors plus exact malicious-component host-boundary checks
• documented separation between driver-representable errors and Canonical ABI rejection

Fresh independent review: Seal cr-3c6qrd approved exact commit 1074af0 after all three prior blocking findings were resolved.

Gates passed: just check, just reproducible, just sigil-check /home/bob/src/sigil/target/release/sigil, and exact WIT drift against the active Sigil Host 1.1 workspace. No release or publication.