Adds a workflow that builds and tests Z3 with AddressSanitizer and
UndefinedBehaviorSanitizer on every push to catch runtime memory errors
and undefined behavior. Runs unit tests, SMT-LIB2 benchmarks, and
regression tests under both sanitizers. Includes a Copilot agentic
workflow to generate summary reports as GitHub Discussions.
Triggered on push (path-filtered to src/) and manual dispatch.
