feat(qbzd): manual daemon connect + persistence + headless login

CastPicker: manual IP:port input for connecting to daemons when
mDNS/avahi is unavailable. Saves recent connections to localStorage
(max 5). One-click reconnect from saved list. Remove button on hover.

Layout: manual input field at top, saved daemons as 'Recent',
mDNS discovered daemons below with scanning indicator.

Login: binds to 0.0.0.0 with auto-detected LAN IP so the OAuth
callback URL works from any browser on the network. 5 min timeout
for remote copy-paste workflow.

i18n: recentDaemons, discoveredDaemons in all 5 locales.

cc

src/lib/i18n/locales/de.json

@@ -565,6 +565,8 @@
     "controllingRemote": "Steuert: {name}",
     "noQbzdFound": "Keine QBZ-Daemons in Ihrem Netzwerk gefunden",
     "noQbzdFoundHint": "Stellen Sie sicher, dass qbzd auf dem Zielgerat lauft",
+    "recentDaemons": "Zuletzt verwendet",
+    "discoveredDaemons": "Im Netzwerk entdeckt",
     "queue": "Warteschlange",
     "upNext": "Als Nächstes",
     "ofTotal": "von",