Add KDoc to the authentication, logout, preferences and share API interfaces

Cover the remaining interfaces of features/login, features/logout,
features/preferences and features/share, along with their members and parameters.

Points recorded here: AccountProviderAccessControl returns true on a build with no
enterprise restriction, ExtraDeveloperOptionsRenderer is bound to a no-op in the
standard build, DirectLogoutView draws nothing until a logout event is sent, and
CacheService exists because clearing a cache destroys the client and the app has
to react.

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

features/preferences/api/src/main/kotlin/io/element/android/features/preferences/api/CacheService.kt

@@ -11,6 +11,9 @@ package io.element.android.features.preferences.api
 import io.element.android.libraries.matrix.api.core.SessionId
 import kotlinx.coroutines.flow.Flow
 
+/**
+ * Announces that a session's cache has been cleared, since clearing it destroys the client and the app has to react.
+ */
 interface CacheService {
     /**
      * A flow of [SessionId], can let the app to know when the

features/preferences/api/src/main/kotlin/io/element/android/features/preferences/api/ExtraDeveloperOptionsRenderer.kt

@@ -14,6 +14,11 @@ import androidx.compose.ui.Modifier
  * Component for rendering extra developer options in the preferences screen.
  */
 interface ExtraDeveloperOptionsRenderer {
+    /**
+     * Draws the extra options. The standard build binds a no-op implementation, so only the builds that actually add options provide a real one.
+     *
+     * @param modifier layout modifier for the container.
+     */
     @Composable
     fun Render(modifier: Modifier)
 }