fix(webtorrent): ensure webseed-only streams are marked healthy

Previously, `probePeers` would mark a stream as unhealthy (healthy: false) if no P2P peers were found, even if a valid webseed was present. This caused the UI to potentially disable playback or show error states for webseed-only content.

This fix ensures that if `peers === 0` but `hasWebSeed` is true, the probe result returns `healthy: true` with reason `"webseed"`.

Added `tests/webtorrent-regression.test.mjs` to verify this behavior and prevent future regressions.

Co-authored-by: PR0M3TH3AN <[email protected]>

js/webtorrent.js

@@ -346,23 +346,25 @@ export class TorrentClient {
 
       torrent.once("error", (err) => {
         const peers = Math.max(0, Math.floor(normalizeNumber(torrent?.numPeers, 0)));
+        const webseedOnly = peers === 0 && hasWebSeed;
         finalize({
-          healthy: false,
-          reason: "error",
+          healthy: webseedOnly,
+          reason: webseedOnly ? "webseed" : "error",
           error: toError(err),
           peers,
-          webseedOnly: peers === 0 && hasWebSeed,
+          webseedOnly,
         });
       });
 
       if (safeTimeout > 0) {
         timeoutId = setTimeout(() => {
           const peers = Math.max(0, Math.floor(normalizeNumber(torrent?.numPeers, 0)));
+          const webseedOnly = peers === 0 && hasWebSeed;
           finalize({
-            healthy: false,
+            healthy: webseedOnly,
             peers,
-            reason: "timeout",
-            webseedOnly: peers === 0 && hasWebSeed,
+            reason: webseedOnly ? "webseed" : "timeout",
+            webseedOnly,
           });
         }, safeTimeout);
       }