Port 6 upstream PRs (PR #939 was already ported):
- #852: Complete HalPowerManager with RAII Lock class, WiFi check in
setPowerSaving, skipLoopDelay overrides for ClearCache/OtaUpdate,
and power lock in Activity render task loops
- #965: Fix paragraph formatting inside list items by tracking
listItemUntilDepth to prevent unwanted line breaks
- #972: Micro-optimizations: std::move in insertFont, const ref for
getDataFromBook parameter
- #971: Remove redundant hasPrintableChars pre-rendering pass from
EpdFont, EpdFontFamily, and GfxRenderer
- #977: Skip unsupported image formats before extraction, add
PARSE_BUFFER_SIZE constant and chapter parse timing
- #975: Fix UITheme memory leak by replacing raw pointer with
std::unique_ptr for currentTheme
Co-authored-by: Cursor <cursoragent@cursor.com>