feat(agent): control triage — LLM false-positive filter over tool findings

ControlTriage composes the pipeline: a deterministic tool finding ->
controls_for(tool,cwe) [control-map LUT] -> grounded judge confirms/refutes ->
TriageOutcome { Unmapped | Confirmed([control ids]) | FalsePositive }. The LLM
enters ONLY here, as an FP filter over tool output (ZeroFalse/IRIS), never as the
detector; only judgments grounded to real code survive. Reuses the judge + core
ground gate + control-map. 3 lib tests (confirm/refute/unmapped).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

compliance-agent/Cargo.toml

@@ -8,6 +8,7 @@ workspace = true
 
 [dependencies]
 compliance-core = { workspace = true, features = ["mongodb", "telemetry", "axum"] }
+control-map = { workspace = true }
 compliance-graph = { path = "../compliance-graph" }
 compliance-dast = { path = "../compliance-dast" }
 # Shared dynamic-execution logic (soft-PLC provisioning + ICS probing), also

compliance-agent/src/controls/mod.rs

@@ -8,7 +8,9 @@
 mod checker;
 mod judge;
 mod oscal_provider;
+mod triage;
 
 pub use checker::GroundedControlChecker;
 pub use judge::{ControlJudge, LlmControlJudge, PROMPT_VERSION};
 pub use oscal_provider::OscalControlsProvider;
+pub use triage::{ControlTriage, TriageOutcome};

compliance-agent/src/controls/triage.rs

@@ -0,0 +1,184 @@
+//! Triage step: confirm/refute a deterministic tool finding against the controls
+//! it maps to (via the `control-map` LUT), grounding the judgment.
+//!
+//! This is where the LLM finally enters — as a **false-positive filter over tool
+//! output**, never as the detector (the ZeroFalse / IRIS pattern). A tool
+//! (semgrep, gitleaks, syft/osv) detects deterministically; `controls_for(tool,
+//! cwe)` attaches the finding to the control(s) it's evidence for; the grounded
+//! judge then confirms or refutes each, and only judgments anchored to real code
+//! survive.
+
+use std::collections::HashMap;
+
+use compliance_core::control_check::{ground, CandidateRegion, ControlCheckSpec};
+use compliance_core::models::Finding;
+use control_map::ControlMap;
+
+use super::judge::ControlJudge;
+
+/// What triage decided for one tool finding.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum TriageOutcome {
+    /// The finding maps to no control in the LUT — keep it, untagged.
+    Unmapped,
+    /// Maps to controls and the grounded judge confirmed at least one — keep the
+    /// finding and tag it with these control ids.
+    Confirmed(Vec<String>),
+    /// Maps to controls but the judge grounded none — treat as a false positive.
+    FalsePositive,
+}
+
+/// Triages tool findings against the control map, confirming with a grounded judge.
+pub struct ControlTriage<J> {
+    judge: J,
+    map: ControlMap,
+    /// Control requirement specs (by control id), built from the ingested catalog.
+    specs: HashMap<String, ControlCheckSpec>,
+}
+
+impl<J: ControlJudge> ControlTriage<J> {
+    pub fn new(judge: J, map: ControlMap, specs: HashMap<String, ControlCheckSpec>) -> Self {
+        Self { judge, map, specs }
+    }
+
+    /// Triage one tool finding. `region` is the code around the finding, used as
+    /// the grounding evidence for the judge.
+    pub async fn triage(&self, finding: &Finding, region: &CandidateRegion) -> TriageOutcome {
+        let Some(cwe) = finding.cwe.as_deref() else {
+            return TriageOutcome::Unmapped;
+        };
+        let mapped = self.map.controls_for(&finding.scanner, cwe);
+        if mapped.is_empty() {
+            return TriageOutcome::Unmapped;
+        }
+
+        let mut confirmed = Vec::new();
+        for entry in mapped {
+            let Some(spec) = self.specs.get(&entry.control) else {
+                continue;
+            };
+            let verdict = self.judge.judge(spec, region).await;
+            // The verdict only counts if it grounds to real code in the region.
+            if ground(spec, region, &verdict, &finding.repo_id).is_some() {
+                confirmed.push(entry.control.clone());
+            }
+        }
+
+        if confirmed.is_empty() {
+            TriageOutcome::FalsePositive
+        } else {
+            TriageOutcome::Confirmed(confirmed)
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use compliance_core::control_check::LlmVerdict;
+    use compliance_core::models::finding::Severity;
+    use compliance_core::models::scan::ScanType;
+
+    struct StubJudge {
+        verdict: LlmVerdict,
+    }
+    impl ControlJudge for StubJudge {
+        async fn judge(&self, _s: &ControlCheckSpec, _r: &CandidateRegion) -> LlmVerdict {
+            self.verdict.clone()
+        }
+    }
+
+    fn specs() -> HashMap<String, ControlCheckSpec> {
+        let mut m = HashMap::new();
+        m.insert(
+            "cra-ai-8".to_string(),
+            ControlCheckSpec {
+                control_id: "cra-ai-8".into(),
+                title: "No default passwords".into(),
+                requirement: "No default credentials".into(),
+                default_cwe: Some("CWE-798".into()),
+                severity: Severity::High,
+            },
+        );
+        m
+    }
+
+    fn semgrep_finding(cwe: &str) -> Finding {
+        let mut f = Finding::new(
+            "repo".into(),
+            "fp1".into(),
+            "semgrep".into(),
+            ScanType::Sast,
+            "hardcoded credential".into(),
+            "desc".into(),
+            Severity::High,
+        );
+        f.cwe = Some(cwe.into());
+        f
+    }
+
+    fn region() -> CandidateRegion {
+        CandidateRegion {
+            file: "src/auth.py".into(),
+            start_line: 1,
+            content: "PASSWORD = \"admin123\"\n".into(),
+        }
+    }
+
+    #[tokio::test]
+    async fn confirmed_finding_is_tagged_with_control() {
+        let triage = ControlTriage::new(
+            StubJudge {
+                verdict: LlmVerdict {
+                    violates: true,
+                    snippet: "PASSWORD = \"admin123\"".into(),
+                    cwe: None,
+                    confidence: 0.9,
+                },
+            },
+            ControlMap::cra().unwrap(),
+            specs(),
+        );
+        let out = triage.triage(&semgrep_finding("CWE-798"), &region()).await;
+        assert_eq!(out, TriageOutcome::Confirmed(vec!["cra-ai-8".to_string()]));
+    }
+
+    #[tokio::test]
+    async fn refuted_mapped_finding_is_false_positive() {
+        // Maps to cra-ai-8, but the judge doesn't confirm (no violation) → FP.
+        let triage = ControlTriage::new(
+            StubJudge {
+                verdict: LlmVerdict {
+                    violates: false,
+                    snippet: String::new(),
+                    cwe: None,
+                    confidence: 0.1,
+                },
+            },
+            ControlMap::cra().unwrap(),
+            specs(),
+        );
+        let out = triage.triage(&semgrep_finding("CWE-798"), &region()).await;
+        assert_eq!(out, TriageOutcome::FalsePositive);
+    }
+
+    #[tokio::test]
+    async fn unmapped_cwe_is_left_untagged() {
+        let triage = ControlTriage::new(
+            StubJudge {
+                verdict: LlmVerdict {
+                    violates: true,
+                    snippet: "PASSWORD = \"admin123\"".into(),
+                    cwe: None,
+                    confidence: 0.9,
+                },
+            },
+            ControlMap::cra().unwrap(),
+            specs(),
+        );
+        let out = triage
+            .triage(&semgrep_finding("CWE-99999"), &region())
+            .await;
+        assert_eq!(out, TriageOutcome::Unmapped);
+    }
+}