refactor(i18n): update remote control copy and default port

Update English translations for the remote-control UI and change the
documented default remote-control port.

- Change default remote control port description from 3000 to 8765 to
  reflect actual configuration.
- Improve remote control UI copy:
  - Add SUBTITLE "Control your IPTV player remotely".
  - Capitalize UP_CHANNEL and DOWN_CHANNEL labels to "Channel Up" and
    "Channel Down" for consistent UI presentation.

These changes clarify the feature and align text with current behavior.

Author: 4gray

apps/web/src/assets/i18n/en.json

@@ -167,7 +167,7 @@
         "REMOTE_CONTROL": "Remote control",
         "REMOTE_CONTROL_DESCRIPTION": "Enable remote control of the application.",
         "REMOTE_CONTROL_PORT": "Remote control port",
-        "REMOTE_CONTROL_PORT_DESCRIPTION": "Port used for remote control of the application. Port 3000 is used by default."
+        "REMOTE_CONTROL_PORT_DESCRIPTION": "Port used for remote control of the application. Port 8765 is used by default."
     },
     "THEMES": {
         "DARK_THEME": "Dark theme",
@@ -342,8 +342,9 @@
     "INFORMATION": "Information",
     "REMOTE_CONTROL": {
         "TITLE": "Remote control",
-        "UP_CHANNEL": "Up channel",
-        "DOWN_CHANNEL": "Down channel",
+        "SUBTITLE": "Control your IPTV player remotely",
+        "UP_CHANNEL": "Channel Up",
+        "DOWN_CHANNEL": "Channel Down",
         "HEADER": "IPTVNator Remote Control",
         "FOOTER": "IPTVNator Remote Control"
     }