test: prove MySQL SQL 0.2 across live dialects

[bobisme]

Summary

• add a portable pinned SingleStoreDB Dev 0.2.35 and MySQL 8.4.6 live acceptance matrix
• prove the packaged component and Lua bridge across typed values, sessions, metadata, errors, limits, timeouts, and transport loss
• add hostile-peer overflow/no-retry evidence, state-machine coverage, and signal-safe container plus volume cleanup

Verification

• full pinned live matrix under rootless Podman with exact image identities and teardown evidence
• just dist, just reproducible, and production Sigil compatibility
• ShellCheck, Python checks, 256-case state-machine property, optimized zeroization
• Seal cr-2mgwpn approved exact commit 2d53e9c

No plugin publication or release is part of this PR.