General fixes (#76)

* Added print functionality to PDF viewer

* feat(pdf): add interactive button support and visibility reveal heuristic

* Moved search state management to MainViewModel and improved search UI interaction.

* Updated `pdfiumandroid` to version 2.0.0 and handled resulting API changes, including nullable page/text page returns and revised native pointer access.

increased compileSdk to 36.

* Fixed Table of Contents (TOC) truncation bug and improved the TOC UI in `PdfViewerScreen`.

- Implemented `getFixedTableOfContents` using reflection to bypass a library issue where sibling nodes were incorrectly truncated during traversal.
- Enhanced the TOC drawer with a nested, expandable tree structure using the new `PdfTocTreeItem` component.
- Added a custom `VerticalScrollbar` with draggable support for better navigation within long TOC lists.
- Integrated `animateColorAsState` and `animateFloatAsState` for smoother UI transitions in the TOC and scrollbar.
- Optimized TOC loading by flattening the tree structure and managing expansion states with `rememberSaveable`.

* Improved zoom pivot calculation and interaction handling in PdfVerticalReader

* Fixed high-res PDF tile bleeding by implementing clipRect in PdfBitmapLayer

* fix(pdf): resolve zoom stuttering, in pagination mode, by removing eager scale snapping

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

@@ -203,6 +203,7 @@ data class ReaderScreenState(
     val lastFolderScanTime: Long? = null,
     val hasUnreadFeedback: Boolean = false,
     val searchQuery: String = "",
+    val isSearchActive: Boolean = false,
     val showFolderMigrationDialog: Boolean = false,
     val isRefreshing: Boolean = false,
     val reflowProgress: Float? = null,
@@ -369,7 +370,23 @@ open class MainViewModel(application: Application) : AndroidViewModel(applicatio
     )
 
     fun onSearchQueryChange(newQuery: String) {
-        _internalState.update { it.copy(searchQuery = newQuery) }
+        _internalState.update {
+            if (it.isSearchActive) {
+                it.copy(searchQuery = newQuery)
+            } else {
+                it
+            }
+        }
+    }
+
+    fun setSearchActive(active: Boolean) {
+        _internalState.update {
+            if (active) {
+                it.copy(isSearchActive = true)
+            } else {
+                it.copy(isSearchActive = false, searchQuery = "")
+            }
+        }
     }
 
     private val _reviewRequestEvent = Channel<Unit>(Channel.BUFFERED)