feat: add access control to channels with various modes

- Introduced AccessMode enum to define channel access levels: Public, PasswordProtected, AccountRequired, and OwnerOnly.
- Updated Channel and ProgrammingBlock entities to include access_mode and access_password_hash fields.
- Enhanced create and update channel functionality to handle access mode and password.
- Implemented access checks in channel routes based on the defined access modes.
- Modified frontend components to support channel creation and editing with access control options.
- Added ChannelPasswordModal for handling password input when accessing restricted channels.
- Updated API calls to include channel and block passwords as needed.
- Created database migrations to add access_mode and access_password_hash columns to channels table.

k-tv-frontend/app/(main)/tv/components/no-signal.tsx

@@ -1,6 +1,6 @@
-import { WifiOff, AlertTriangle, Loader2 } from "lucide-react";
+import { WifiOff, AlertTriangle, Loader2, Lock } from "lucide-react";
 
-type NoSignalVariant = "no-signal" | "error" | "loading";
+type NoSignalVariant = "no-signal" | "error" | "loading" | "locked";
 
 interface NoSignalProps {
   variant?: NoSignalVariant;
@@ -27,6 +27,11 @@ const VARIANTS: Record<
     heading: "Loading",
     defaultMessage: "Tuning in…",
   },
+  locked: {
+    icon: <Lock className="h-10 w-10 text-zinc-600" />,
+    heading: "Access Restricted",
+    defaultMessage: "You don't have permission to watch this channel.",
+  },
 };
 
 export function NoSignal({ variant = "no-signal", message, children }: NoSignalProps) {