Fix Unread/startup crash; add reader-mode toggle and swipe navigation

- Root cause of the reported crashes: observeUnread/observeByFeed/
  observeSaved used SELECT *, pulling feedContentHtml/extractedContent
  (potentially large per-article blobs) just to render a list row.
  With 107 feeds worth of real articles this blows past Android's
  CursorWindow/memory limits, scaling with item count -- and since
  Unread is now the landing screen, it crashed at startup too. Added
  an ArticleListItem projection excluding the heavy content columns;
  list queries now only select what a row actually renders.
- FilterRuleEngine now takes a small Titled interface (title/feedId)
  instead of the full entity, so it works with both ArticleEntity and
  the new lighter projection.
- Reader-mode toggle: a button in the reader to manually switch
  between feed-provided content and Readability-extracted full text,
  matching Inoreader's full-text-view toggle (previously only an
  automatic fallback when feed content was thin).
- Swipe between articles: ReaderScreen now wraps a HorizontalPager over
  a snapshot of the current list's article-id order, so swiping moves
  to the next/previous article. Snapshotted rather than live, since
  marking an article read would otherwise drop it from the live Unread
  query mid-swipe and shift every later page underneath the user.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EZ7ikw2ukGJFTHE3bJS7zL

1 files changed, 12 insertions, 4 deletions

diff --git a/app/src/main/java/org/terst/feedreader/ui/MainActivity.kt b/app/src/main/java/org/terst/feedreader/ui/MainActivity.kt
index c080d89..e1300f0 100644
--- a/app/src/main/java/org/terst/feedreader/ui/MainActivity.kt
+++ b/app/src/main/java/org/terst/feedreader/ui/MainActivity.kt
@@ -63,17 +63,25 @@ fun FeedReaderApp() {
             val feedId = decodeNavArg(backStackEntry.arguments?.getString("feedId") ?: UNREAD_FEED_ID)
             ArticleListScreen(
                 feedId = feedId,
-                onOpenArticle = { articleId -> navController.navigate("reader/${encodeNavArg(articleId)}") },
+                onOpenArticle = { articleId ->
+                    navController.navigate("reader/${encodeNavArg(feedId)}/${encodeNavArg(articleId)}")
+                },
                 onBack = { navController.popBackStack() },
                 onOpenFeedList = { navController.navigate("feeds") }
             )
         }
         composable(
-            "reader/{articleId}",
-            arguments = listOf(navArgument("articleId") { type = NavType.StringType })
+            "reader/{feedId}/{articleId}",
+            arguments = listOf(
+                navArgument("feedId") { type = NavType.StringType },
+                navArgument("articleId") { type = NavType.StringType }
+            )
         ) { backStackEntry ->
+            val feedId = decodeNavArg(backStackEntry.arguments?.getString("feedId") ?: UNREAD_FEED_ID)
             val articleId = decodeNavArg(backStackEntry.arguments?.getString("articleId") ?: "")
-            ReaderScreen(articleId = articleId, onBack = { navController.popBackStack() })
+            // feedId here is the list the article was opened from (Unread/Saved/a specific
+            // feed) -- ReaderScreen uses it to build the swipe queue of sibling articles.
+            ReaderScreen(feedId = feedId, initialArticleId = articleId, onBack = { navController.popBackStack() })
         }
         composable("addFeed") {
             AddFeedScreen(onDone = { navController.popBackStack() })