fix: add header bar and fix bottom spacing in BookInfo

Draw the standard header (clock, battery, title) via GUI.drawHeader().
Replace hardcoded MARGIN with theme metrics for content positioning.
Content area now starts below the header and stops above button hints
so the last lines are never obscured.

Made-with: Cursor

chat-summaries/2026-03-08_23-00-summary.md

@@ -36,9 +36,17 @@
 - Display order: Title, Author, Series, Publisher, Date, Subjects, Rating (N/5), Language, ISBN, Contributor, File Size, Rights, Description
 - Rating displayed as `N / 5` (Calibre stores 0-10, divided by 2)
 
+### 6. BookInfoActivity UI Integration (`src/activities/home/BookInfoActivity.cpp`)
+- Added `GUI.drawHeader()` call to show the standard header bar (clock, battery, "Book Info" title)
+- Replaced hardcoded `MARGIN = 20` with theme metrics (`contentSidePadding`, `topPadding`, `headerHeight`, etc.)
+- Content now starts below the header bar using `metrics.topPadding + metrics.headerHeight + metrics.verticalSpacing`
+- Y-culling stops content above button hints using `pageH - metrics.buttonHintsHeight - metrics.verticalSpacing`
+- `contentHeight` includes bottom padding for button hints so scrolling accounts for the reserved hint area
+
 ## Commits
 - `8025e6f` — `feat: parse and display all available EPUB metadata fields`
-- (pending) — `refactor: consolidate Epub blank strings, simplify BookInfo buildLayout`
+- `efa727e` — `refactor: consolidate Epub blank strings, simplify BookInfo buildLayout`
+- (pending) — `fix: add header bar and fix bottom spacing in BookInfo`
 
 ## Follow-up
 - Existing book caches will auto-invalidate (version 6 → 7) and regenerate on next load