Initial content scanner integration (#7139)

* Create a `ContentScanner` component:

- Add `:features:contentscanner:api` module with the interface.
- Implement the concrete component using the Rust SDK in `:libraries:matrix:impl`.

This can be used to both set up the content scanner media fetching in the SDK Client and manually scanning media sources from the Android side

* Create `ContentScannerUrlProvider` in a new `:features:contentscaner:api` module as a noop implementation

Use it as a placeholder for the code to instantiate a `RustContentScanner` with the fetched URL and set it as part of the SDK client.

* Expose the optional `ContentScanner` in the `@SessionScope`

* Split the storage part of the Element well-known retriever so it can be reused for the non-session bound retriever.

Also add the new `content_scanner_url` field to it.

This will be used by the enterprise code to fetch the actual content scanner url.

* Bump enterprise commit to have access to the actual content scanner url provider implementation

* Fix tests and lint issues

* Use the right namespace for `:features:contentscanner:api`, also use the right namespace for `impl`

---------

Co-authored-by: Benoit Marty <benoitm@element.io>

libraries/matrix/api/src/main/kotlin/io/element/android/libraries/matrix/api/MatrixClient.kt

@@ -38,6 +38,7 @@ import io.element.android.libraries.matrix.api.room.alias.ResolvedRoomAlias
 import io.element.android.libraries.matrix.api.room.location.BeaconInfoUpdate
 import io.element.android.libraries.matrix.api.roomdirectory.RoomDirectoryService
 import io.element.android.libraries.matrix.api.roomlist.RoomListService
+import io.element.android.libraries.matrix.api.scanner.ContentScanner
 import io.element.android.libraries.matrix.api.spaces.SpaceService
 import io.element.android.libraries.matrix.api.sync.SlidingSyncVersion
 import io.element.android.libraries.matrix.api.sync.SyncService
@@ -71,6 +72,7 @@ interface MatrixClient {
     val ignoredUsersFlow: StateFlow<ImmutableList<UserId>>
     val roomMembershipObserver: RoomMembershipObserver
     val ownBeaconInfoUpdates: Flow<BeaconInfoUpdate>
+    val contentScanner: ContentScanner?
     suspend fun getJoinedRoom(roomId: RoomId): JoinedRoom?
     suspend fun getRoom(roomId: RoomId): BaseRoom?
     suspend fun findDM(userId: UserId): Result<RoomId?>

libraries/matrix/api/src/main/kotlin/io/element/android/libraries/matrix/api/scanner/ContentScanner.kt

@@ -0,0 +1,27 @@
+/*
+ * Copyright (c) 2026 Element Creations Ltd.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial.
+ * Please see LICENSE files in the repository root for full details.
+ */
+
+package io.element.android.libraries.matrix.api.scanner
+
+import io.element.android.libraries.matrix.api.media.MediaSource
+
+/**
+ * Component used to manually scan media content for potential security risks.
+ *
+ * While the Matrix SDK automatically scans media content we load if a content scanner instance is provided, this interface allows for scanning
+ * some media sources in advance without actually loading their contents, which can be useful for pre-fetching scenarios.
+ */
+interface ContentScanner {
+    /**
+     * Manually scans the given [mediaSource] for potential security risks.
+     *
+     * @param mediaSource The media source to scan.
+     * @return A [Result] containing a [Boolean] indicating whether the content is safe (true) or potentially unsafe (false).
+     * If the scan fails, the [Result] will contain an exception.
+     */
+    suspend fun scan(mediaSource: MediaSource): Result<Boolean>
+}

libraries/matrix/api/src/main/kotlin/io/element/android/libraries/matrix/api/scanner/ContentScannerUrlProvider.kt

@@ -0,0 +1,18 @@
+/*
+ * Copyright (c) 2026 Element Creations Ltd.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial.
+ * Please see LICENSE files in the repository root for full details.
+ */
+
+package io.element.android.libraries.matrix.api.scanner
+
+/**
+ * Provides the URL of the content scanner service for a given homeserver, if any is set up.
+ */
+fun interface ContentScannerUrlProvider {
+    /**
+     * Returns the URL of the content scanner service for the given [homeserver], or `null` if no content scanner is set up.
+     */
+    suspend fun getContentScannerUrl(homeserver: String): Result<String?>
+}