Windows ga (#358)

* Enhance Cloud TTS with navigation controls and shared UI overlay in desktop app

* Refactor Cloud TTS voice settings and remove standalone settings overlay on desktop app

* Persist reader window state and improve slider interaction in desktop app

* Improve PDF page transitions and refine focus management in desktop app

* Refactor scrollbar interaction and adjust desktop modal focus handling

* Improve PDF sidecar synchronization and cross-platform metadata compatibility

* Refactor PDF annotation comment logic to shared module and implement Desktop UI

* Refactor reader screen to use tap-to-toggle and full-width styling in desktop app

* Refactor reader workspace layout and chrome-panel interactions

* Implement global search keyboard shortcuts and focusable chrome layers

* Implement flavor-specific legal links and update the About UI

* Refactor reader UI controls on desktop app

* Enhance desktop folder sync with background metadata extraction and improved error handling

* Refactor Library UI and remove redundant Home tab in desktop app

* Add custom tooltips to reader icon buttons in desktop app

* Integrate app theme controls into reader interfaces on desktop

* Add right-to-left pagination support and improve focus restoration on desktop app

* Improve EPUB pagination geometry and diagnostic logging for layout cutoffs on desktop app

* Update desktop reader defaults and implement settings migration

* Implement block-based position tracking in ReaderLocator

* Enhance EPUB highlighting reliability in desktop app

* Add support for custom reader themes and update highlight palette logic in desktop app

* Replace the Tools panel with a "More" dropdown menu and refactor account UI

* Implement account profile header in desktop sidebar

* Implement cloud sync reliability improvements and sidebar toggle on desktop app

* Improve EPUB annotation synchronization and highlight mapping accuracy in desktop app

* Integrate WebView2 for EPUB vertical rendering on Windows

* Refactor reader layout logic and enhance WebView2 diagnostics

* Improve vertical reading layout and WebView2 resizing on Desktop

* Refine vertical reading mode layout and margin handling

* Enhance reader locator precision and Desktop mode-switching reliability

* Implement chapter-level caching and warm-start pagination in desktop app

* Replace bundled KCEF with native system webviews via SWT

* Refactor EPUB page info bar visibility and layout logic

* Improve PDF toolbar persistence and fix tab reactivation logic

* Enable multi-selection and bulk operations for custom fonts

* Refactor instrumentation tests

* Add EPUB UI test fixture and initial instrumentation tests

* Expand EpubReader UI tests and improve accessibility

* Add instrumentation tests and test tags for library and reader screens

* Enhance OPDS parser logic and catalog integration

* Add support for toggling local synchronization on a per-folder basis.

* Implement tri-state sizing for the TTS overlay

* Persist TTS overlay size across sessions

* Refactor reader brightness control and add incremental step buttons

* Improve CSS support, pagination control, and style-aware semantic caching

* Improve link handling, interaction, and diagnostics in the paginated reader

* crash fixes

* Implement persistent pending removal for external files

* Implement book-specific word replacements

* Add native vertical reading mode with custom renderer

* Implement text selection and navigation improvements for the native vertical reader

* Implement locator-based navigation and improved vertical scrolling in native vertical mode in epub

* Implement lazy loading and chapter prefetching for native vertical reader

* Improve window lifecycle and disposal handling on Desktop

* Optimize vertical reading performance in desktop app

* Enhance TTS start accuracy and diagnostic logging on desktop

* Refactor AI settings visibility on desktop

* Improve pagination height measurement and enhance cutoff diagnostics

* Implement lifecycle management and improve justified text splitting for pagination

* Refine AI usage tracking and force AI feature visibility on Desktop

* Add descriptive context comments and usage examples to string and plural resources.

* Optimize performance and memory usage in search and state mapping

* Replace reader page sliders with minimal slider and navigation controls

* Add support for CBT comic archives

* Harden file path validation and XML parsing to prevent security vulnerabilities

* Implement local account profile caching and optimize desktop performance

* Improve desktop persistence reliability and add Linux secure storage support

* Improved PDF zoom stability and layout prediction during zoom commits

* Improved PDF spread layout prediction, reader focus restoration, and account profile caching

* Enhance highlight precision and scoping using block-local offsets and CFIs

* Enhance cloud book content synchronization and background downloads

* Implement granular timestamp tracking for reading positions and PDF annotations

* Restrict diagnostic logging and stack traces to debug builds

* Refine PDF page gaps and reader chrome interaction logic

* Refactor PDF highlight rendering and overhaul Desktop sidebar UI

* Implement a new interaction dock and undo/redo history for PDF annotations in desktop

* Enhance PDF color picker and improve navigation scroll restoration

* Add highlight palette customization and improve selection menu UI in desktop app epub reader

* Enhance desktop shelf management and library organization

app/src/main/java/com/aryan/reader/AppNavigation.kt

@@ -21,6 +21,7 @@ package com.aryan.reader
 
 import android.os.Build
 import timber.log.Timber
+import androidx.activity.compose.BackHandler
 import androidx.annotation.RequiresApi
 import androidx.compose.animation.AnimatedVisibility
 import androidx.compose.animation.fadeIn
@@ -80,6 +81,18 @@ object AppDestinations {
     const val SETTINGS_SCREEN_ROUTE = "settings_screen_route"
 }
 
+fun shouldInterceptAppNavBack(
+    currentRoute: String?,
+    hasPreviousBackStackEntry: Boolean,
+    isCurrentEntryResumed: Boolean
+): Boolean {
+    if (!hasPreviousBackStackEntry || !isCurrentEntryResumed) return false
+    return currentRoute != null &&
+        currentRoute != AppDestinations.MAIN_ROUTE &&
+        currentRoute != AppDestinations.PDF_VIEWER_ROUTE &&
+        currentRoute != AppDestinations.EPUB_READER_ROUTE
+}
+
 private fun NavHostController.isReadyForBackStackChange(): Boolean {
     return currentBackStackEntry?.lifecycle?.currentState == Lifecycle.State.RESUMED
 }
@@ -166,6 +179,11 @@ fun AppNavigation(
     val miniBarBottomPadding = readerTtsMiniBarBottomPaddingDp(
         isOnMainRoute = currentRoute == AppDestinations.MAIN_ROUTE
     ).dp
+    val shouldInterceptBack = shouldInterceptAppNavBack(
+        currentRoute = currentRoute,
+        hasPreviousBackStackEntry = navController.previousBackStackEntry != null,
+        isCurrentEntryResumed = currentBackStackEntry?.lifecycle?.currentState == Lifecycle.State.RESUMED
+    )
 
     LaunchedEffect(currentRoute, uiState.selectedFileType, uiState.isLoading, uiState.selectedEpubBook, uiState.selectedPdfUri) {
         if (!uiState.isLoading) {
@@ -195,6 +213,10 @@ fun AppNavigation(
     }
 
     Box(modifier = Modifier.fillMaxSize()) {
+        BackHandler(enabled = shouldInterceptBack) {
+            navController.popBackStackIfReady()
+        }
+
         NavHost(navController = navController, startDestination = AppDestinations.MAIN_ROUTE) {
         composable(AppDestinations.MAIN_ROUTE) {
             Timber.d("Navigating to Main Screen (${AppDestinations.MAIN_ROUTE}).")
@@ -315,7 +337,7 @@ fun AppNavigation(
                             },
                             onRenderModeChange = viewModel::setRenderMode,
                             customFonts = customFonts,
-                            onImportFont = viewModel::importFont,
+                            onImportFonts = viewModel::importFonts,
                             viewModel = viewModel
                         )