Improve portable launch, forge persistence, and operator auth UX.

Persist build extra_files for Build Manager history, print dashboard login on every start, add libp2p for Mesh P2P forge, defer WebSocket until login, and split devrun.bat from LAUNCH.bat with USB deck auto-detection.

server/web/src/pages/BuildManagerPage.tsx

@@ -221,7 +221,7 @@ function BuildCard({
         <div className="bm-downloads-label font-tech">DOWNLOAD</div>
         <div className="bm-downloads-row">
           <DownloadButton
-            apiPath={api.buildDownloadUrl(build.id)}
+            apiPath={build.download_url || api.buildDownloadUrl(build.id)}
             filename={exeName}
             className="btn btn-primary bm-dl-btn"
           >
@@ -234,6 +234,16 @@ function BuildCard({
           >
             ↓ Uninstall script
           </AuthDownloadButton>
+          {build.extra_files?.map((f) => (
+            <DownloadButton
+              key={f.file_name}
+              apiPath={api.buildArtifactUrl(build.id, f.file_name)}
+              filename={f.file_name}
+              className="btn btn-outline bm-dl-btn"
+            >
+              ↓ {f.file_name}
+            </DownloadButton>
+          ))}
         </div>
       </div>