feat: ✨ route Coil image loads through authenticated OPDS OkHttp client

Coil's default singleton ImageLoader has no awareness of the OPDS
BasicAuthInterceptor, so cover requests against authenticated calibre-web
instances 401 silently and the catalog grid only ever shows the
gradient+initials fallback. Implement coil.ImageLoaderFactory on
EReaderApp with an ImageLoader built against the existing
OpdsHttpClient.okHttp, so Coil inherits Basic auth (and any future
interceptors) automatically. AppContainer's opdsHttp is promoted from
private to public to be reachable from the Application class.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: vitofico

app/src/main/java/io/theficos/ereader/EReaderApp.kt

@@ -1,14 +1,21 @@
 package io.theficos.ereader
 
 import android.app.Application
+import coil.ImageLoader
+import coil.ImageLoaderFactory
 import io.theficos.ereader.di.AppContainer
 
-class EReaderApp : Application() {
+class EReaderApp : Application(), ImageLoaderFactory {
     lateinit var container: AppContainer
         private set
 
     override fun onCreate() {
         super.onCreate()
         container = AppContainer(this)
     }
+
+    override fun newImageLoader(): ImageLoader =
+        ImageLoader.Builder(this)
+            .okHttpClient(container.opdsHttp.okHttp)
+            .build()
 }

app/src/main/java/io/theficos/ereader/di/AppContainer.kt

@@ -20,7 +20,7 @@ class AppContainer(context: Context) {
 
     val credentialStore: CalibreCredentialStore = CalibreCredentialStore(appContext)
 
-    private val opdsHttp = OpdsHttpClient(credentialStore)
+    val opdsHttp = OpdsHttpClient(credentialStore)
     val opdsClient: OpdsClient = OpdsClient(opdsHttp.okHttp)
     val bookDownloader: BookDownloader = BookDownloader(
         okHttp = opdsHttp.okHttp,