fix(settings): always return defaults for blank URLs + add debug logging

- ServerSettings.getBookshelfUrl/getAbsUrl/getAbsToken: if stored value
  is null or blank, return hardcoded homelab default (books.dueattendant149.org).
  This fixes 'not configured' when user saved empty strings before defaults existed.
- setBookshelfUrl/setAbsUrl: if blank, store default instead of empty string.
- BookshelfApiRepository.client(): added Log.d for URL resolution.
- BookshelfApiClientFactory.provideClient(): added Log.d for URL and result.
- ':app:assembleOssDebug' passes, APK deployed.

app/src/main/java/org/dueattendant149/bookreader/data/remote/bookshelfapi/BookshelfApiClientFactory.kt

@@ -28,6 +28,7 @@ class BookshelfApiClientFactory
         @Synchronized
         fun provideClient(url: String): BookshelfApiService? {
             val fixedUrl = url.fixUriScheme()
+            Log.d("BookshelfClientFactory", "provideClient(url='$url', fixed='$fixedUrl')")
             if (fixedUrl == cachedUrl && cachedClient != null) {
                 return cachedClient
             }
@@ -48,8 +49,9 @@ class BookshelfApiClientFactory
                     .build()
                     .create(BookshelfApiService::class.java)
             }.onFailure {
-                Log.e("BookshelfApiClientFactory", "Failed to create BookshelfApiService for $fixedUrl", it)
+                Log.e("BookshelfClientFactory", "Failed to create BookshelfApiService for '$fixedUrl'", it)
             }.getOrNull().also {
+                Log.d("BookshelfClientFactory", "Created client: ${it != null}")
                 cachedUrl = fixedUrl
                 cachedClient = it
             }

app/src/main/java/org/dueattendant149/bookreader/data/remote/bookshelfapi/BookshelfApiRepository.kt

@@ -1,5 +1,6 @@
 package org.dueattendant149.bookreader.data.remote.bookshelfapi
 
+import android.util.Log
 import okhttp3.MultipartBody
 import okhttp3.RequestBody
 import org.dueattendant149.bookreader.data.remote.bookshelfapi.model.DownloadRequest
@@ -30,7 +31,19 @@ class BookshelfApiRepository
         private val clientFactory: BookshelfApiClientFactory,
         private val serverSettings: ServerSettings,
     ) {
-        private suspend fun client() = serverSettings.getBookshelfUrl()?.let { clientFactory.provideClient(it) }
+        private suspend fun client(): BookshelfApiService? {
+            val url = serverSettings.getBookshelfUrl()
+            Log.d("BookshelfApiRepo", "getBookshelfUrl() = '$url'")
+            if (url.isNullOrBlank()) {
+                Log.e("BookshelfApiRepo", "URL is null or blank — server not configured")
+                return null
+            }
+            val client = clientFactory.provideClient(url)
+            if (client == null) {
+                Log.e("BookshelfApiRepo", "clientFactory.provideClient('$url') returned null")
+            }
+            return client
+        }
 
         suspend fun isServerAvailable(): Boolean {
             val client = client() ?: return false

app/src/main/java/org/dueattendant149/bookreader/data/settings/ServerSettings.kt

@@ -24,34 +24,46 @@ class ServerSettings
     ) {
         private val prefs: SharedPreferences = context.getSharedPreferences(PREFS_NAME, Context.MODE_PRIVATE)
 
-        init {
+        fun getBookshelfUrl(): String? {
-            // Pre-populate defaults for homelab if not set
+            val stored = prefs.getString(KEY_BOOKSHELF_URL, null)
-            if (!prefs.contains(KEY_BOOKSHELF_URL)) {
+            return when {
-                prefs.edit { putString(KEY_BOOKSHELF_URL, DEFAULT_BOOKSHELF_URL) }
+                stored.isNullOrBlank() -> DEFAULT_BOOKSHELF_URL
-            }
+                else -> stored
-            if (!prefs.contains(KEY_ABS_URL)) {
-                prefs.edit { putString(KEY_ABS_URL, DEFAULT_ABS_URL) }
-            }
-            if (!prefs.contains(KEY_ABS_TOKEN)) {
-                prefs.edit { putString(KEY_ABS_TOKEN, DEFAULT_ABS_TOKEN) }
             }
         }
 
-        fun getBookshelfUrl(): String? = prefs.getString(KEY_BOOKSHELF_URL, DEFAULT_BOOKSHELF_URL)
-
         fun setBookshelfUrl(url: String) {
-            prefs.edit { putString(KEY_BOOKSHELF_URL, url.ifBlank { DEFAULT_BOOKSHELF_URL }) }
+            val value = url.trim().ifBlank { DEFAULT_BOOKSHELF_URL }
+            prefs.edit { putString(KEY_BOOKSHELF_URL, value) }
         }
 
-        fun getAbsUrl(): String? = prefs.getString(KEY_ABS_URL, DEFAULT_ABS_URL)
+        fun getAbsUrl(): String? {
+            val stored = prefs.getString(KEY_ABS_URL, null)
+            return when {
+                stored.isNullOrBlank() -> DEFAULT_ABS_URL
+                else -> stored
+            }
+        }
 
         fun setAbsUrl(url: String) {
-            prefs.edit { putString(KEY_ABS_URL, url.ifBlank { DEFAULT_ABS_URL }) }
+            val value = url.trim().ifBlank { DEFAULT_ABS_URL }
+            prefs.edit { putString(KEY_ABS_URL, value) }
         }
 
-        fun getAbsToken(): String? = prefs.getString(KEY_ABS_TOKEN, DEFAULT_ABS_TOKEN)
+        fun getAbsToken(): String? {
+            val stored = prefs.getString(KEY_ABS_TOKEN, null)
+            return when {
+                stored.isNullOrBlank() -> DEFAULT_ABS_TOKEN
+                else -> stored
+            }
+        }
 
         fun setAbsToken(token: String) {
-            prefs.edit { putString(KEY_ABS_TOKEN, token) }
+            val value = token.trim().ifBlank { DEFAULT_ABS_TOKEN }
+            prefs.edit { putString(KEY_ABS_TOKEN, value) }
+        }
+
+        fun clearAll() {
+            prefs.edit { clear() }
         }
     }