Add /api/subtitles/debug endpoint to diagnose XML-RPC connectivity

Hits XML-RPC login + Interstellar search and returns token prefix,
result count, and found languages. Helps diagnose why search returns [].

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

apps/server/src/routes/subtitles.ts

@@ -74,6 +74,25 @@ function extractField(xml: string, field: string): string[] {
 // No-op: kept so old client builds don't 404 on /config
 router.get('/config', (_req, res) => res.json({ provider: 'xmlrpc' }))
 
+// Diagnostic endpoint — hit this to check if XML-RPC login works from this server
+router.get('/debug', async (_req, res) => {
+  try {
+    const tok = await getToken()
+    // Quick search for a well-known title
+    const resp = await xmlCall('SearchSubtitles',
+      `<param><value><string>${tok}</string></value></param>` +
+      `<param><value><array><data><value><struct>` +
+      `<member><name>sublanguageid</name><value><string>all</string></value></member>` +
+      `<member><name>imdbid</name><value><string>0816692</string></value></member>` +
+      `</struct></value></data></array></value></param>`)
+    const ids = extractField(resp, 'IDSubtitleFile')
+    const langs = extractField(resp, 'SubLanguageID')
+    res.json({ ok: true, token: tok.slice(0, 8) + '...', resultCount: ids.length, languages: [...new Set(langs)] })
+  } catch (err: any) {
+    res.status(502).json({ ok: false, error: err?.message })
+  }
+})
+
 router.get('/search', async (req, res) => {
   const { imdb_id, type, languages, season, episode } = req.query as Record<string, string>
   if (!imdb_id) { res.status(400).json({ error: 'Missing imdb_id' }); return }