Add KDoc to the features/invitepeople API interfaces

Document InvitePeopleState and each of its properties, InvitePeopleEvents,
InvitePeopleRenderer and the presenter factory.

The state properties now say what drives them, in particular that
createRoomFromDmAction covers the case of inviting a third person into an
existing direct message, and that the factory accepts a null room for that flow.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

features/invitepeople/api/src/main/kotlin/io/element/android/features/invitepeople/api/InvitePeopleEvents.kt

@@ -8,6 +8,9 @@
 
 package io.element.android.features.invitepeople.api
 
+/**
+ * Events the invite people UI sends to its presenter through [InvitePeopleState.eventSink].
+ */
 interface InvitePeopleEvents {
     data object SendInvites : InvitePeopleEvents
     data object CloseSearch : InvitePeopleEvents

features/invitepeople/api/src/main/kotlin/io/element/android/features/invitepeople/api/InvitePeoplePresenter.kt

@@ -13,7 +13,14 @@ import io.element.android.libraries.matrix.api.core.RoomId
 import io.element.android.libraries.matrix.api.room.JoinedRoom
 
 interface InvitePeoplePresenter : Presenter<InvitePeopleState> {
+    /**
+     * Creates a presenter for one invite flow.
+     */
     interface Factory {
+        /**
+         * @param joinedRoom the room to invite into, or `null` when the room does not exist yet, as when inviting from a direct message.
+         * @param roomId the id of the room to invite into.
+         */
         fun create(
             joinedRoom: JoinedRoom?,
             roomId: RoomId,

features/invitepeople/api/src/main/kotlin/io/element/android/features/invitepeople/api/InvitePeopleRenderer.kt

@@ -11,7 +11,16 @@ package io.element.android.features.invitepeople.api
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.Modifier
 
+/**
+ * Renders the invite people UI, so that other screens can embed it without depending on its implementation.
+ */
 interface InvitePeopleRenderer {
+    /**
+     * Draws the invite list and its search field.
+     *
+     * @param state the state produced by [InvitePeoplePresenter].
+     * @param modifier layout modifier for the container.
+     */
     @Composable
     fun Render(
         state: InvitePeopleState,

features/invitepeople/api/src/main/kotlin/io/element/android/features/invitepeople/api/InvitePeopleState.kt

@@ -11,10 +11,22 @@ package io.element.android.features.invitepeople.api
 import io.element.android.libraries.architecture.AsyncAction
 import io.element.android.libraries.matrix.api.core.RoomId
 
+/**
+ * State of the invite people UI, produced by an [InvitePeoplePresenter] and consumed by an [InvitePeopleRenderer].
+ */
 interface InvitePeopleState {
+    /** Whether the send button should be enabled, i.e. at least one user is selected and the user has the permission. */
     val canInvite: Boolean
+
+    /** Whether the search field currently has focus, which the host screen uses to adapt its own layout. */
     val isSearchActive: Boolean
+
+    /** Progress of the invite request, so the UI can show a loader and surface failures. */
     val sendInvitesAction: AsyncAction<Unit>
+
+    /** Progress of turning a direct message into a room, which happens when inviting a third person into a DM. */
     val createRoomFromDmAction: AsyncAction<RoomId>
+
+    /** Where the UI sends its events. */
     val eventSink: (InvitePeopleEvents) -> Unit
 }