feat: add local files provider with indexing and rescan functionality

- Implemented LocalFilesProvider to manage local video files.
- Added LocalIndex for in-memory and SQLite-backed indexing of video files.
- Introduced scanning functionality to detect video files and extract metadata.
- Added API endpoints for listing collections, genres, and series based on provider capabilities.
- Enhanced existing routes to check for provider capabilities before processing requests.
- Updated frontend to utilize provider capabilities for conditional rendering of UI elements.
- Implemented rescan functionality to refresh the local files index.
- Added database migration for local files index schema.

k-tv-frontend/app/(main)/dashboard/page.tsx

@@ -11,6 +11,8 @@ import {
   useGenerateSchedule,
 } from "@/hooks/use-channels";
 import { useAuthContext } from "@/context/auth-context";
+import { useConfig } from "@/hooks/use-config";
+import { useRescanLibrary } from "@/hooks/use-library";
 import { api } from "@/lib/api";
 import { toast } from "sonner";
 import { useQueryClient } from "@tanstack/react-query";
@@ -34,11 +36,14 @@ export default function DashboardPage() {
   const { token } = useAuthContext();
   const queryClient = useQueryClient();
   const { data: channels, isLoading, error } = useChannels();
+  const { data: config } = useConfig();
+  const capabilities = config?.provider_capabilities;
 
   const createChannel = useCreateChannel();
   const updateChannel = useUpdateChannel();
   const deleteChannel = useDeleteChannel();
   const generateSchedule = useGenerateSchedule();
+  const rescanLibrary = useRescanLibrary();
 
   // Channel ordering — persisted to localStorage
   const [channelOrder, setChannelOrder] = useState<string[]>([]);
@@ -226,6 +231,22 @@ export default function DashboardPage() {
           </p>
         </div>
         <div className="flex gap-2">
+          {capabilities?.rescan && (
+            <Button
+              onClick={() =>
+                rescanLibrary.mutate(undefined, {
+                  onSuccess: (d) => toast.success(`Rescan complete: ${d.items_found} files found`),
+                  onError: () => toast.error("Rescan failed"),
+                })
+              }
+              disabled={rescanLibrary.isPending}
+              title="Rescan local files directory"
+              className="border-zinc-700 text-zinc-400 hover:text-zinc-100"
+            >
+              <RefreshCw className={`size-4 ${rescanLibrary.isPending ? "animate-spin" : ""}`} />
+              Rescan library
+            </Button>
+          )}
           {channels && channels.length > 0 && (
             <Button
               onClick={handleRegenerateAll}
@@ -346,6 +367,7 @@ export default function DashboardPage() {
         onSubmit={handleEdit}
         isPending={updateChannel.isPending}
         error={updateChannel.error?.message}
+        capabilities={capabilities}
       />
 
       <ScheduleSheet