feat(onboarding): scan-trigger endpoint + wizard Run-Scan button

Complete the onboard -> scan -> results loop in-UI:
- POST /api/v1/targets/{id}/scan (404s unknown targets) spawns run_scan, which
  dispatches to the unified pipeline under UNIFIED_PIPELINE.
- Wizard Done step gains a "Run scan" button (server fn trigger_target_scan)
  with inline status, so a user can onboard and kick off a scan without curl.

Passes fmt + clippy -D warnings (agent, dashboard server + web).

Closes #126, #127. Refs #131, #133, #118.

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

compliance-dashboard/src/infrastructure/onboarding.rs

@@ -105,3 +105,19 @@ pub async fn fetch_applicable_scans(id: String) -> Result<ApplicableScansRespons
         .await
         .map_err(|e| ServerFnError::new(e.to_string()))
 }
+
+/// Trigger a scan for a target.
+#[server]
+pub async fn trigger_target_scan(id: String) -> Result<serde_json::Value, ServerFnError> {
+    let resp = super::agent_client::agent_request(
+        reqwest::Method::POST,
+        &format!("/api/v1/targets/{id}/scan"),
+    )
+    .await?
+    .send()
+    .await
+    .map_err(|e| ServerFnError::new(e.to_string()))?;
+    resp.json()
+        .await
+        .map_err(|e| ServerFnError::new(e.to_string()))
+}

compliance-dashboard/src/pages/onboarding.rs

@@ -2,7 +2,7 @@ use dioxus::prelude::*;
 
 use crate::components::page_header::PageHeader;
 use crate::infrastructure::onboarding::{
-    create_target, detect_target, fetch_applicable_scans, ArtifactInputDto,
+    create_target, detect_target, fetch_applicable_scans, trigger_target_scan, ArtifactInputDto,
 };
 
 /// (value, label, one-line description) for the 9 target families.
@@ -113,6 +113,8 @@ pub fn OnboardingPage() -> Element {
     let mut error = use_signal(|| Option::<String>::None);
     let mut scans = use_signal(Vec::<serde_json::Value>::new);
     let mut suggested = use_signal(|| Option::<String>::None);
+    let mut created_id = use_signal(|| Option::<String>::None);
+    let mut scan_msg = use_signal(|| Option::<String>::None);
 
     let step_now = step();
     let can_advance_type = !name().trim().is_empty() && !target_type().trim().is_empty();
@@ -290,7 +292,27 @@ pub fn OnboardingPage() -> Element {
                             ScanRow { scan: s }
                         }
                     }
-                    div { style: "margin-top: 16px;",
+                    if let Some(msg) = scan_msg() {
+                        div { style: "margin-top: 8px; color: var(--success, #2a2);", "{msg}" }
+                    }
+                    div { style: "margin-top: 16px; display: flex; gap: 8px;",
+                        button {
+                            class: "btn btn-primary",
+                            onclick: move |_| {
+                                if let Some(id) = created_id() {
+                                    scan_msg.set(Some("Scan triggered...".to_string()));
+                                    spawn(async move {
+                                        match trigger_target_scan(id).await {
+                                            Ok(_) => scan_msg.set(Some(
+                                                "Scan started — findings will appear as it runs.".to_string(),
+                                            )),
+                                            Err(e) => scan_msg.set(Some(format!("Failed to start scan: {e}"))),
+                                        }
+                                    });
+                                }
+                            },
+                            "Run scan"
+                        }
                         button {
                             class: "btn btn-secondary",
                             onclick: move |_| {
@@ -301,6 +323,8 @@ pub fn OnboardingPage() -> Element {
                                 artifacts.write().clear();
                                 scans.write().clear();
                                 suggested.set(None);
+                                created_id.set(None);
+                                scan_msg.set(None);
                                 error.set(None);
                             },
                             "Onboard another"
@@ -348,6 +372,7 @@ pub fn OnboardingPage() -> Element {
                                             .and_then(|s| s.as_str())
                                             .map(String::from);
                                         if let Some(id) = id {
+                                            created_id.set(Some(id.clone()));
                                             if let Ok(sc) = fetch_applicable_scans(id.clone()).await {
                                                 scans.set(sc.data.scans);
                                             }