Offline dictionary (#45)

* Added support for external dictionary apps and a dictionary settings sheet.

* Refactored external dictionary integration and improved package visibility

 - Updated `AndroidManifest.xml` with `<queries>` for common dictionary apps and intent actions (`PROCESS_TEXT`, `SEARCH`, `SEND`) to support Android 11+ package visibility.
 - Refactored `ExternalDictionaryHelper` to streamline dictionary discovery using `Intent.ACTION_PROCESS_TEXT` and `colordict.intent.action.SEARCH`.
 - Added a package blocklist in `ExternalDictionaryHelper` to filter out system services (e.g., Samsung Pass, GMS) from dictionary lists.
  - Simplified `launchDictionary` logic to prioritize `PROCESS_TEXT` intents.
 - Fixed a bug in `PdfViewerScreen` to only show the dictionary upsell dialog when `useOnlineDictionary` is enabled.

* Refactored dictionary settings into a dialog and updated dictionary selection logic.

- Renamed `DictionarySettingsSheet` to `DictionarySettingsDialog` and converted it from a bottom sheet to a formal dialog.
- Redesigned the dictionary settings UI with a clearer distinction between AI and external app modes.
- Added a "Search" option to the external dictionary list that triggers a web search.
- Updated `ExternalDictionaryHelper` to include a package blocklist and support for generic web search intents.
- Simplified `PdfHelper` by removing Pro user checks for the "Dictionary" action.
- Updated icons for dictionary settings across the EPUB and PDF readers.

app/src/main/java/com/aryan/reader/epubreader/EpubReaderControls.kt

@@ -67,6 +67,7 @@ import androidx.compose.foundation.shape.CircleShape
 import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.automirrored.filled.ArrowBack
+import androidx.compose.material.icons.automirrored.filled.MenuBook
 import androidx.compose.material.icons.filled.Add
 import androidx.compose.material.icons.filled.ArrowDropDown
 import androidx.compose.material.icons.filled.Check
@@ -148,6 +149,7 @@ fun EpubReaderTopBar(
     onStartAutoScroll: () -> Unit,
     onOpenTtsSettings: () -> Unit,
     onOpenDeviceVoiceSettings: () -> Unit,
+    onOpenDictionarySettings: () -> Unit,
     searchFocusRequester: androidx.compose.ui.focus.FocusRequester,
     modifier: Modifier = Modifier,
     onToggleReflow: (() -> Unit)? = null,
@@ -190,6 +192,12 @@ fun EpubReaderTopBar(
                         overflow = TextOverflow.Ellipsis,
                         modifier = Modifier.weight(1f)
                     )
+                    IconButton(onClick = onOpenDictionarySettings) {
+                        Icon(
+                            painter = painterResource(id = R.drawable.dictionary),
+                            contentDescription = "Dictionary Settings"
+                        )
+                    }
                     Box {
                         var showMoreMenu by remember { mutableStateOf(false) }
                         IconButton(onClick = { showMoreMenu = true }) {