Fix extraction regression on kottke; add Older view, mark-read-from-here

- ReaderExtractor: the un-hide-before-extracting fix (for soft paywalls
  like West Hawaii Today) was unconditional -- it also un-hid normal,
  legitimately-collapsed chrome (kottke's footer/membership notice), which
  Readability then folded into the result alongside the real article.
  Reported live with a screenshot showing the extracted content wrapped in
  site footer boilerplate. Now tries the normal (hidden-respecting) pass
  first and only falls back to the un-hide pass if that came back thin
  (<500 chars), keeping whichever pass actually found more text. Verified
  live: the same kottke article now stays clean and stable (no delayed
  switch to the footer version).

- New Unread/Older split: the default Unread view is now clamped to the
  last 72 hours (RECENT_WINDOW_MS); the rest of the unread backlog moved
  to a new "Older" view (new FeedListScreen row, ArticleDao.observeUnread
  now takes a cutoff, observeOlderUnread/observeUnreadCount/
  observeOlderUnreadCount added). Undated articles are kept in the main
  Unread view rather than silently dropped from both. Verified live: 150
  recent / 1172 older, summing to the prior combined total.

- "Mark read from here": long-press an article row to mark it and
  everything older in that same filtered list as read in one batch
  (re-added ArticleDao.markReadBatch, this time as an explicit,
  confirmed action -- not the implicit on-scroll version that was
  reverted earlier). Verified live: confirmed a 147-article batch: the
  tapped article and older were marked read, newer ones above it were not.

- BACKLOG.md: added a YouTube-embeds note (JS is off in the reader
  WebView, so embeds currently show broken -- rough shape is a tap-to-play
  thumbnail rather than turning JS on for third-party content).

1 files changed, 13 insertions, 0 deletions

diff --git a/BACKLOG.md b/BACKLOG.md
index 6e95f7b..49f20d0 100644
--- a/BACKLOG.md
+++ b/BACKLOG.md
@@ -34,3 +34,16 @@ relying on manual tagging carried over from another tool.
 - Out of scope for now: any automated "find where the author moved"
   logic — that's a manual research task when a feed's actually declared
   dead, not something to build detection for.
+
+## YouTube embeds
+
+**Motivation:** the reader's WebView runs with JavaScript off (feed/extracted
+content never needs it, and it keeps articles from running arbitrary
+scripts) — so a YouTube iframe embedded in an article currently just shows
+as a broken/blank box instead of a playable video or thumbnail.
+
+**Rough shape (not yet built):** detect a YouTube iframe/embed URL in the
+extracted or feed-provided HTML and swap it for a tap-to-play thumbnail
+(image + play button) that opens the video in the YouTube app/browser on
+tap, rather than trying to make the embed actually play inline (which would
+mean turning JS back on for untrusted third-party content).