artifacts tab: inline PDF preview via iframe (task #19)

frontend/src/components/dashboard/MissionCanvas.tsx

@@ -83,6 +83,7 @@ export function MissionCanvas({
   const [launching, setLaunching] = useState(false);
   const [refining, setRefining] = useState(false);
   const [phaseBusy, setPhaseBusy] = useState<string | null>(null);
+  const [pdfPreviewId, setPdfPreviewId] = useState<string | null>(null);
 
   const load = useCallback(async () => {
     if (!selectedId) {
@@ -567,9 +568,14 @@ export function MissionCanvas({
             {mission.artifacts.length === 0 ? (
               <Empty label="no artifacts yet — phases produce them as they run" />
             ) : (
-              mission.artifacts.map((a) => (
+              mission.artifacts.map((a) => {
+                const isPreviewing = pdfPreviewId === a.id;
+                return (
                   <div
                     key={a.id}
+                    style={{ display: "flex", flexDirection: "column", gap: 8 }}
+                  >
+                    <div
                       style={{
                         padding: 11,
                         borderRadius: 10,
@@ -590,6 +596,20 @@ export function MissionCanvas({
                         </div>
                       </div>
                       {a.rendered_pdf_path ? (
+                        <>
+                          <button
+                            type="button"
+                            onClick={() =>
+                              setPdfPreviewId(isPreviewing ? null : a.id)
+                            }
+                            style={{
+                              ...secondaryBtn,
+                              padding: "5px 10px",
+                              fontSize: 11,
+                            }}
+                          >
+                            {isPreviewing ? "Hide" : "Preview"}
+                          </button>
                           <a
                             href={a.rendered_pdf_path}
                             target="_blank"
@@ -601,8 +621,9 @@ export function MissionCanvas({
                               textDecoration: "none",
                             }}
                           >
-                      Open PDF
+                            Open
                           </a>
+                        </>
                       ) : a.render_pdf_status !== "skip" ? (
                         <span
                           style={{
@@ -618,7 +639,22 @@ export function MissionCanvas({
                         </span>
                       ) : null}
                     </div>
-              ))
+                    {isPreviewing && a.rendered_pdf_path && (
+                      <iframe
+                        src={a.rendered_pdf_path}
+                        title={a.title ?? a.path}
+                        style={{
+                          width: "100%",
+                          height: 640,
+                          border: "1px solid rgba(255,255,255,.06)",
+                          borderRadius: 8,
+                          background: "#0a0a0d",
+                        }}
+                      />
+                    )}
+                  </div>
+                );
+              })
             )}
           </div>
         )}