Code-review BLOCKER B1. Reaffirms D-011: a `re` stdlib fallback defeats the
OPSEC-safe-regex guarantee because hostile C2 output can trigger catastrophic
backtracking. The `[:1MB]` slice cap does not mitigate that — re-evaluating
a malicious pattern over 1 MB of attacker-controlled text is still a worker
freeze.
- `mimic.templating.filters` now imports `re2` unconditionally and raises
`RuntimeError` at module load if the binding is absent. No `re` import,
no `_HAS_RE2` branch, no `_FALLBACK_MAX_INPUT`.
- `pyproject.toml` already pinned `google-re2 >= 1.1, < 2.0`; this commit
hardens the import path to actually enforce it.
- New test `test_re2_is_required` asserts the binding is wired in.
90f8141cfc