cerebro-regression-tests

# Cerebro Regression Tests ## Instructions 1. Reproduce the reported bug class with the smallest package-level test. 2. Prefer table-driven Go tests for parser, validator, projection, graph, and source connector edge cases; Rust kernel behavior belongs in the owning crate's tests (property tests where the crate already uses them). 3. Include security boundary cases for URL, host, tenant, auth, pagination, size-limit, and error-mapping fixes. 4. Keep fixtures local to the package unless an existing shared fixture pattern already exists. 5. Run the focused package test with `-count=1 -v` (Go) or `cargo test -p <crate>` (Rust), then `make changed-check`, then `make verify` when feasible. ## Success Criteria - The new test fails against the unfixed behavior or clearly asserts the regression boundary. - The production fix is minimal and covered by the new test.