fix: align Cisco Firepower filter and rule contracts

Author: kryonsx

filters/audits/cisco-firepower.md

@@ -0,0 +1,40 @@
+# Cisco Firepower normalization and rule review
+
+Correct IPsec failures, scan/shun outcomes, ACL precedence, invalid CEL and syslog severity.
+
+This draft targets UTMStack `v11`. It contains 1 filter changes
+and 0 rule changes for this technology only. Review covered
+1 filter configurations and 5 matching shipped rule files.
+Unchanged rules are listed in the regression manifest; they are not duplicated in the diff.
+
+## Contract and validation
+
+- Compared exact standard names/types with go-sdk v1.1.31 and the supplied UTMStack dictionaries.
+- Checked documented pipeline ordering, rename/move behavior, open vendor log fields,
+  event-side versus alert-side fields, and surviving fields used by affected rule predicates/history/grouping.
+- Strict SDK configuration decoding and actual CEL compilation pass for this scope.
+- 12 synthetic normalization cases pass, including SDK Event conversion and any
+  trigger predicate assertions recorded in the manifest.
+- The scoped alerts module tests and `git diff --check` pass with the shared contract runner applied.
+
+The shared alert-contract PR supplies the reusable Go runner for the manifest in
+`plugins/alerts/testdata/filter-contracts/cisco-firepower.json`. Apply that support before running `go test ./...` in `plugins/alerts`.
+
+The model starts from synthetic extraction results. It does not run complex grok,
+JSON/KV/XML/CSV extraction, time conversion, dynamic plugins, historical OpenSearch
+queries, or the closed EventProcessor. Raw vendor logs and resulting alerts must
+still be checked in staging before rollout. No customer false-positive reduction
+has been measured and no production rollout is included.
+
+
+
+## References
+
+- [SDK schema](https://github.com/threatwinds/go-sdk/blob/v1.1.31/plugins/plugins.proto)
+- [Filter steps](https://github.com/threatwinds/go-sdk/wiki/Filter-Steps-Reference)
+- [Standard event schema](https://github.com/threatwinds/go-sdk/wiki/Standard-Event-Schema)
+- [Rule implementation](https://github.com/threatwinds/go-sdk/wiki/Implementing-Rules)
+
+`afterEvents`, empty noncapturing grok names, supported numeric strings, and custom
+`log.*` fields are accepted. Existing textual protocol casing and vendor action names
+are preserved unless a concrete consumer mismatch requires correction.