feat: add OpenTelemetry trace spans to all handlers and pipeline functions

Add #[tracing::instrument(skip_all)] to 44 functions:
- 19 API handlers in mod.rs
- 3 chat handlers, 6 DAST handlers, 7 graph handlers
- 2 pipeline orchestrator functions
- 7 scanner functions (sbom, semgrep, gitleaks, cve, lint, patterns)

This generates trace spans for SigNoz visibility into request
latency, scan pipeline stages, and error tracking.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

compliance-agent/src/api/handlers/mod.rs

@@ -179,10 +179,12 @@ pub struct SbomVersionDiff {
 type AgentExt = Extension<Arc<ComplianceAgent>>;
 type ApiResult<T> = Result<Json<ApiResponse<T>>, StatusCode>;
 
+#[tracing::instrument(skip_all)]
 pub async fn health() -> Json<serde_json::Value> {
     Json(serde_json::json!({ "status": "ok" }))
 }
 
+#[tracing::instrument(skip_all)]
 pub async fn stats_overview(Extension(agent): AgentExt) -> ApiResult<OverviewStats> {
     let db = &agent.db;
 
@@ -253,6 +255,7 @@ pub async fn stats_overview(Extension(agent): AgentExt) -> ApiResult<OverviewSta
     }))
 }
 
+#[tracing::instrument(skip_all)]
 pub async fn list_repositories(
     Extension(agent): AgentExt,
     Query(params): Query<PaginationParams>,
@@ -283,6 +286,7 @@ pub async fn list_repositories(
     }))
 }
 
+#[tracing::instrument(skip_all)]
 pub async fn add_repository(
     Extension(agent): AgentExt,
     Json(req): Json<AddRepositoryRequest>,
@@ -329,6 +333,7 @@ pub async fn add_repository(
     }))
 }
 
+#[tracing::instrument(skip_all)]
 pub async fn get_ssh_public_key(
     Extension(agent): AgentExt,
 ) -> Result<Json<serde_json::Value>, StatusCode> {
@@ -337,6 +342,7 @@ pub async fn get_ssh_public_key(
     Ok(Json(serde_json::json!({ "public_key": public_key.trim() })))
 }
 
+#[tracing::instrument(skip_all)]
 pub async fn trigger_scan(
     Extension(agent): AgentExt,
     Path(id): Path<String>,
@@ -351,6 +357,7 @@ pub async fn trigger_scan(
     Ok(Json(serde_json::json!({ "status": "scan_triggered" })))
 }
 
+#[tracing::instrument(skip_all)]
 pub async fn delete_repository(
     Extension(agent): AgentExt,
     Path(id): Path<String>,
@@ -397,6 +404,7 @@ pub async fn delete_repository(
     Ok(Json(serde_json::json!({ "status": "deleted" })))
 }
 
+#[tracing::instrument(skip_all)]
 pub async fn list_findings(
     Extension(agent): AgentExt,
     Query(filter): Query<FindingsFilter>,
@@ -465,6 +473,7 @@ pub async fn list_findings(
     }))
 }
 
+#[tracing::instrument(skip_all)]
 pub async fn get_finding(
     Extension(agent): AgentExt,
     Path(id): Path<String>,
@@ -485,6 +494,7 @@ pub async fn get_finding(
     }))
 }
 
+#[tracing::instrument(skip_all)]
 pub async fn update_finding_status(
     Extension(agent): AgentExt,
     Path(id): Path<String>,
@@ -505,6 +515,7 @@ pub async fn update_finding_status(
     Ok(Json(serde_json::json!({ "status": "updated" })))
 }
 
+#[tracing::instrument(skip_all)]
 pub async fn bulk_update_finding_status(
     Extension(agent): AgentExt,
     Json(req): Json<BulkUpdateStatusRequest>,
@@ -534,6 +545,7 @@ pub async fn bulk_update_finding_status(
     ))
 }
 
+#[tracing::instrument(skip_all)]
 pub async fn update_finding_feedback(
     Extension(agent): AgentExt,
     Path(id): Path<String>,
@@ -554,6 +566,7 @@ pub async fn update_finding_feedback(
     Ok(Json(serde_json::json!({ "status": "updated" })))
 }
 
+#[tracing::instrument(skip_all)]
 pub async fn sbom_filters(
     Extension(agent): AgentExt,
 ) -> Result<Json<serde_json::Value>, StatusCode> {
@@ -585,6 +598,7 @@ pub async fn sbom_filters(
     })))
 }
 
+#[tracing::instrument(skip_all)]
 pub async fn list_sbom(
     Extension(agent): AgentExt,
     Query(filter): Query<SbomFilter>,
@@ -640,6 +654,7 @@ pub async fn list_sbom(
     }))
 }
 
+#[tracing::instrument(skip_all)]
 pub async fn export_sbom(
     Extension(agent): AgentExt,
     Query(params): Query<SbomExportParams>,
@@ -771,6 +786,7 @@ const COPYLEFT_LICENSES: &[&str] = &[
     "MPL-2.0",
 ];
 
+#[tracing::instrument(skip_all)]
 pub async fn license_summary(
     Extension(agent): AgentExt,
     Query(params): Query<SbomFilter>,
@@ -816,6 +832,7 @@ pub async fn license_summary(
     }))
 }
 
+#[tracing::instrument(skip_all)]
 pub async fn sbom_diff(
     Extension(agent): AgentExt,
     Query(params): Query<SbomDiffParams>,
@@ -905,6 +922,7 @@ pub async fn sbom_diff(
     }))
 }
 
+#[tracing::instrument(skip_all)]
 pub async fn list_issues(
     Extension(agent): AgentExt,
     Query(params): Query<PaginationParams>,
@@ -936,6 +954,7 @@ pub async fn list_issues(
     }))
 }
 
+#[tracing::instrument(skip_all)]
 pub async fn list_scan_runs(
     Extension(agent): AgentExt,
     Query(params): Query<PaginationParams>,