Studying: daily five minutes, reading list, plan-day studies use your template

- Home: "Your five minutes": a rotating Observe/Interpret/Apply prompt on the
  passage whose matching note is thinnest in your own words, a 5:00 clock and a
  box that appends to that note. Pasting is blocked; sessions show in Insights.
- Study: a Reading list tab (R) for the study: books and articles to consult,
  with a note and a tick; merges across devices.
- Starting a study from a reading-plan day now uses the notes template you last
  picked when starting a study by hand (logic moved to utils/planStudy.js).

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

src/components/ShortcutsHelp.jsx

@@ -24,7 +24,7 @@ const BY_PAGE = {
     ['← →', 'Previous / next chunk'],
     ['1  2  3', 'Write in Observe / Interpret / Apply'],
     ['Esc', 'Leave a note box (then keys work again)'],
-    ['C  W  X  P', 'Commentary / Word study / Cross-refs / People & places'],
+    ['C  W  X  P  R', 'Commentary / Word study / Cross-refs / People & places / Reading list'],
     ['V', 'Compare passages or translations'],
   ],
 };