## Summary
* Fixes#475
* Fixes#477
* Closes#428
## Additional Context
* Updates to
`src/activities/reader/EpubReaderChapterSelectionActivity.cpp` are
copied verbatim from #433 (thanks to @jonasdiemer)
* Update to `src/activities/settings/KOReaderSettingsActivity.cpp` per
discussion with @itsthisjustin at #428
Tested on my device with several books and koreader sync turned on and
off.
---
### AI Usage
Did you use AI tools to help write this code? _NO_
## Summary
Addresses
https://github.com/crosspoint-reader/crosspoint-reader/issues/504
- Reverts book progress % to showing as an integer instead of with a
decimal place
- This was changed to 1 decimal point of precision in
https://github.com/crosspoint-reader/crosspoint-reader/pull/232 from
what I can tell
- As this wasn't the primary intention of that PR, I'm assuming it was
left in accidentally
IMO having a decimal place of precision is too much for something as
vague as book completion percent. This de-clutters the status bar and
prevents extra updates as you change pages.
---
### AI Usage
YES
When reading on Landscape Counter ClockWise mode, the left/right button
appear inverted: the upper button (left) goes down and the lower button
(right) goes up.
Discussion: #449
## Summary
* **What is the goal of this PR?** (e.g., Implements the new feature for
file uploading.)
Add a new configuration for the front buttons: Back, Confirm, Right,
Left
---
### AI Usage
While CrossPoint doesn't have restrictions on AI tools in contributing,
please be transparent about their usage as it
helps set the right context for reviewers.
Did you use AI tools to help write this code? _**NO**_
## Summary
* Add additional punctuation marks to the list of characters that can be
immediately followed by a line break even where there is no explicit
space
## Additional Context
* Huge appreciation to @osteotek for his amazing work on hyphenation.
Reading on the device is so much better now.
* I am getting bad line breaks when ellipses (…) are between words and
book file does not explicitly include some kind of breaking space.
* Per
[discussion](https://github.com/crosspoint-reader/crosspoint-reader/pull/305#issuecomment-3765411406),
several new characters are added in this PR to the `isExplicitHyphen`
list to allow line breaks immediately after them:
Character | Unicode | Usage | Why include it?
-- | -- | -- | --
Solidus (Slash) | U+002F | / | Essential for breaking URLs and "and/or"
constructs.
Backslash | U+005C | \ | Critical for technical text, file paths, and
coding documentation.
Underscore | U+005F | _ | Prevents "runaway" line lengths in usernames
or code snippets.
Middle Dot | U+00B7 | · | Acts as a semantic separator in dictionaries
or stylistic lists.
Ellipsis | U+2026 | … | Prevents justification failure when dialogue
lacks following spaces.
Midline Horizontal Ellipsis | U+22EF | ⋯ | Useful for mathematical
sequences and technical notation.
### Example:
This shows an example of what line breaking looks like *with* this PR.
Note the line break after "matter…" (which would not previously have
been allowed). It's particularly important here because the book
includes non-breaking spaces in "Mr. Aldrich" and "Mr. Rockefeller."

---
### AI Usage
While CrossPoint doesn't have restrictions on AI tools in contributing,
please be transparent about their usage as it
helps set the right context for reviewers.
Did you use AI tools to help write this code? **PARTIALLY**
* master:
chore: Cut release 0.15.0
fix: OPDS browser OOM (#403)
docs: Add detailed webserver documentation (#446)
feat: invalidate cache on web uploads and opds downloads and add Clear Cache action (#393)
fix: hard reset via RTS pin after flashing firmware (#437)
fix: Skip negative screen coordinates only after we read the bitmap row. (#431)
Reclaim space if we don't show battery Percentage (#352)
feat: Include superscripts and subscripts in fonts (#463)
My Library: Tab bar w/ Recent Books + File Browser (#250)
feat: adding categories to settings screen (#331)
## Summary
- Rewrite OpdsParser to stream parsing instead of full content
- Fix OOM due to big http xml response
Closes#385
---
### AI Usage
While CrossPoint doesn't have restrictions on AI tools in contributing,
please be transparent about their usage as it
helps set the right context for reviewers.
Did you use AI tools to help write this code? _**NO**_
## More detailed documentation
* **What is the goal of this PR?**
Add more information about the exposed webserver.
* **What changes are included?**
Detailed documentation for the webserver endpoints
(`./docs/webserver-endpoints.md`)
Adding a table of content so it is easier to navigate directly to the
section you're interested on (Almost all `.md` files or at least all
those relevant)
## Additional Context
Not sure if this would get accepted but I thought it might be useful for
those trying to create separate apps that would sync files to the
device. It was at least to me trying to upload files using python as
stated
[here](https://github.com/crosspoint-reader/crosspoint-reader/discussions/434#discussioncomment-15545349)
---
### AI Usage
While CrossPoint doesn't have restrictions on AI tools in contributing,
please be transparent about their usage as it
helps set the right context for reviewers.
Did you use AI tools to help write this code? _**PARTIALLY**_
## Summary
When uploading or downloading an updated ebook from SD/WebUI/OPDS with
same the filename the `.crosspoint` cache is not cleared. This can lead
to issues with the Table of Contents and hangs when switching between
chapters.
I encountered this issue in two places:
- When I need to do further ePub cleaning using Calibre after I load an
ePub and find that some of its formatting should be cleaned up. When I
reprocess the same book and want to place it back in the same location I
need a way to invalidate the cache.
- When syncing RSS feed generated epubs. I generate news ePubs with
filenames like `news-outlet.epub` and so every day when I fetch new news
the crosspoint cache needs to be cleared to load that file.
This change offers the following features:
- On web uploads, if the file already exists, the cache for that file is
cleared
- On OPDS downloads, if the file already exists, the cache for that file
is cleared
- There's now an action for `Clear Cache` in the Settings page which can
clear the cache for all books
Addresses
https://github.com/crosspoint-reader/crosspoint-reader/issues/281
---
### AI Usage
While CrossPoint doesn't have restrictions on AI tools in contributing,
please be transparent about their usage as it
helps set the right context for reviewers.
Did you use AI tools to help write this code? PARTIALLY
---------
Co-authored-by: Dave Allie <dave@daveallie.com>
## Summary
* Disables going to sleep after uploading new firmware
* Makes developer experience easier
---
### AI Usage
While CrossPoint doesn't have restrictions on AI tools in contributing,
please be transparent about their usage as it
helps set the right context for reviewers.
Did you use AI tools to help write this code? _**< NO >**_
---------
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
## Summary
Give space to the chapter title if we don't show battery percentage.
---
### AI Usage
While CrossPoint doesn't have restrictions on AI tools in contributing,
please be transparent about their usage as it
helps set the right context for reviewers.
Did you use AI tools to help write this code? _**NO**_
---------
Co-authored-by: Dave Allie <dave@daveallie.com>
## Summary
* Include superscripts and subscripts in fonts
## Additional Context
* Original change came from
https://github.com/crosspoint-reader/crosspoint-reader/pull/248
---
### AI Usage
While CrossPoint doesn't have restrictions on AI tools in contributing,
please be transparent about their usage as it
helps set the right context for reviewers.
Did you use AI tools to help write this code? No
---------
Co-authored-by: cor <cor@pruijs.dev>
# Summary
This PR introduces a reusable Tab Bar component and combines the Recent
Books and File Browser into a unified tabbed page called "My Library"
accessible from the Home screen.
## Features
### New Tab Bar Component
A flexible, reusable tab bar component added to `ScreenComponents` that
can be used throughout the application.
### New Scroll Indicator Component
A page position indicator for lists that span multiple pages.
**Features:**
- Up/down arrow indicators
- Current page fraction display (e.g., "1/3")
- Only renders when content spans multiple pages
### My Library Activity
A new unified view combining Recent Books and File Browser into a single
tabbed page.
**Tabs:**
- **Recent** - Shows recently opened books
- **Files** - Browse SD card directory structure
**Navigation:**
- Up/Down or Left/Right: Navigate through list items
- Left/Right (when first item selected): Switch between tabs
- Confirm: Open selected book or enter directory
- Back: Go up directory (Files tab) or return home
- Long press Back: Jump to root directory (Files tab)
**UI Elements:**
- Tab bar with selection indicator
- Scroll/page indicator on right side
- Side button hints (up/down arrows)
- Dynamic bottom button labels ("BACK" in subdirectories, "HOME" at
root)
## Tab Bar Usage
The tab bar component is designed to be reusable across different
activities. Here's how to use it:
### Basic Example
```cpp
#include "ScreenComponents.h"
void MyActivity::render() const {
renderer.clearScreen();
// Define tabs with labels and selection state
std::vector<TabInfo> tabs = {
{"Tab One", currentTab == 0}, // Selected when currentTab is 0
{"Tab Two", currentTab == 1}, // Selected when currentTab is 1
{"Tab Three", currentTab == 2} // Selected when currentTab is 2
};
// Draw tab bar at Y position 15, returns height of the tab bar
int tabBarHeight = ScreenComponents::drawTabBar(renderer, 15, tabs);
// Position your content below the tab bar
int contentStartY = 15 + tabBarHeight + 10; // Add some padding
// Draw content based on selected tab
if (currentTab == 0) {
renderTabOneContent(contentStartY);
} else if (currentTab == 1) {
renderTabTwoContent(contentStartY);
} else {
renderTabThreeContent(contentStartY);
}
renderer.displayBuffer();
}
```
Video Demo: https://share.cleanshot.com/P6NBncFS
<img width="250"
src="https://github.com/user-attachments/assets/07de4418-968e-4a88-9b42-ac5f53d8a832"
/>
<img width="250"
src="https://github.com/user-attachments/assets/e40201ed-dcc8-4568-b008-cd2bf13ebb2a"
/>
<img width="250"
src="https://github.com/user-attachments/assets/73db269f-e629-4696-b8ca-0b8443451a05"
/>
---------
Co-authored-by: Dave Allie <dave@daveallie.com>
## Summary
* **What is the goal of this PR?** (e.g., Fixes a bug in the user
authentication module, Implements the new feature for
file uploading.)
As we get more settings, I think it makes sense to do categories for
them. This just allows users to find the settings easier and navigate to
them.
* **What changes are included?**
## Additional Context
* Add any other information that might be helpful for the reviewer
(e.g., performance implications, potential risks, specific areas to
focus on).
Co-authored-by: dpoulter <daniel@yoco.com>
Co-authored-by: Dave Allie <dave@daveallie.com>
* origin:
fix: truncate chapter names that are too long (#422)
feat: dict based Hyphenation (#305)
fix: render U+FFFD replacement character instead of ? (#366)
fix: Invert colors on home screen cover overlay when recent book is selected (#390)
Adds KOReader Sync support (#232)
feat: Change keyboard "caps" to "shift" & Wrap Keyboard (#377)
fix: XTC 1-bit thumb BMP polarity inversion (#373)
## Summary
* **What is the goal of this PR?** (e.g., Implements the new feature for
file uploading.)
- Implements a fix to truncate chapter names that exceeds display width
* **What changes are included?**
- Implements a fix to truncate chapter names that exceeds display width
## Additional Context
* Add any other information that might be helpful for the reviewer
(e.g., performance implications, potential risks,
specific areas to focus on).
- Prior to the fix, if the book contains multiple chapters with names
longer than the display width, there is a noticeable delay when
scrolling through the list of chapters.
Serial output of the issue:
```
[25673] [ACT] Entering activity: EpubReaderChapterSelection
[25693] [GFX] !! Outside range (485, 65) -> (65, -6)
[25693] [GFX] !! Outside range (486, 65) -> (65, -7)
[25693] [GFX] !! Outside range (487, 65) -> (65, -8)
[25693] [GFX] !! Outside range (488, 65) -> (65, -9)
[25693] [GFX] !! Outside range (485, 66) -> (66, -6)
[25693] [GFX] !! Outside range (486, 66) -> (66, -7)
[25694] [GFX] !! Outside range (487, 66) -> (66, -8)
[25694] [GFX] !! Outside range (484, 67) -> (67, -5)
[25694] [GFX] !! Outside range (485, 67) -> (67, -6)
[25694] [GFX] !! Outside range (486, 67) -> (67, -7)
[25694] [GFX] !! Outside range (483, 68) -> (68, -4)
[25694] [GFX] !! Outside range (484, 68) -> (68, -5)
[25694] [GFX] !! Outside range (485, 68) -> (68, -6)
```
---
### AI Usage
While CrossPoint doesn't have restrictions on AI tools in contributing,
please be transparent about their usage as it
helps set the right context for reviewers.
Did you use AI tools to help write this code? _**NO**_
Co-authored-by: Dave Allie <dave@daveallie.com>
## Summary
* Adds (optional) Hyphenation for English, French, German, Russian
languages
## Additional Context
* Included hyphenation dictionaries add approximately 280kb to the flash
usage (German alone takes 200kb)
* Trie encoded dictionaries are adopted from hypher project
(https://github.com/typst/hypher)
* Soft hyphens (and other explicit hyphens) take precedence over
dict-based hyphenation. Overall, the hyphenation rules are quite
aggressive, as I believe it makes more sense on our smaller screen.
---------
Co-authored-by: Dave Allie <dave@daveallie.com>
The current behavior of rendering `?` for an unknown Unicode character
can be hard to distinguish from a typo. Use the standard Unicode
"replacement character" instead, that's what it's designed for:
https://en.wikipedia.org/wiki/Specials_(Unicode_block)
I'm making this PR as a draft because I'm not sure I did everything that
was needed to change the character set covered by the fonts. Running
that script is in its own commit. If this is proper, I'll rebase/squash
into one commit and un-draft.
Co-authored-by: Maeve Andrews <maeve@git.mail.maeveandrews.com>
## Summary
* Fixes#388
## Additional Context
* Tested on my own device
* See images at #388 for what home screen looked like before.
* With this PR the home screen shows the following (selected and
unselected recent book × cover image rendered or not)

---
### AI Usage
While CrossPoint doesn't have restrictions on AI tools in contributing,
please be transparent about their usage as it
helps set the right context for reviewers.
Did you use AI tools to help write this code? **YES**
---------
Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
## Summary
- Adds KOReader progress sync integration, allowing CrossPoint to sync
reading positions with other
KOReader-compatible devices
- Stores credentials securely with XOR obfuscation
- Uses KOReader's partial MD5 document hashing for cross-device book
matching
- Syncs position via percentage with estimated XPath for compatibility
# Features
- Settings: KOReader Username, Password, and Authenticate options
- Sync from chapters menu: "Sync Progress" option appears when
credentials are configured
- Bidirectional sync: Can apply remote progress or upload local progress
---------
Co-authored-by: Dave Allie <dave@daveallie.com>
## Summary
* This PR solves issue
https://github.com/crosspoint-reader/crosspoint-reader/issues/357 in the
first commit
* I then added an additional commit which means when you reach the end
of the keyboard, if you go 'beyond', you wrap back to the other side.
* This replaces existing behaviour, so if you would rather this be
removed, let me know and I'll just do the `caps` -> `shift` change
## Additional Context
### Screenshots for the new shift display
I thought it might not fit and need column size changes, but ended up
fitting fine, see screenshots showing this below:
<img width="573" height="366" alt="image"
src="https://github.com/user-attachments/assets/b8f6a4ec-94f5-4f5e-b9a6-06cc5f250ddb"
/>
<img width="570" height="308" alt="image"
src="https://github.com/user-attachments/assets/7d775518-4784-4120-a20a-a9dc67af8565"
/>
### Gif showing the wrap-around of the text

---
### AI Usage
Did you use AI tools to help write this code? **PARTIALLY** - used to
double check the text wrapping had no edge-cases. (It did also suggest
rewriting the function, but I decided that was too big of a change for a
working part of the codebase, for now!)
## Summary
* **What is the goal of this PR?** (e.g., Implements the new feature for
file uploading.)
* **What changes are included?**
- Fix inverted colors in Continue Reading cover image for 1-bit XTC
files
## Additional Context
* Add any other information that might be helpful for the reviewer
(e.g., performance implications, potential risks,
specific areas to focus on).
- Fix `grayValue = pixelBit ? 0 : 255` → `grayValue = pixelBit ? 255 :
0` in `lib/Xtc/Xtc.cpp`
- The thumb BMP generation had inverted polarity compared to cover BMP
generation
- bit=0 should be black, bit=1 should be white (matching the BMP palette
order)
- Update misleading comment about XTC polarity
---
### AI Usage
While CrossPoint doesn't have restrictions on AI tools in contributing,
please be transparent about their usage as it
helps set the right context for reviewers.
Did you use AI tools to help write this code? _**PARTIALLY**_
## Summary
* Implements #380, allowing the user to see the device's MAC address in
order to register on wifi networks
## Additional Context
* Although @markatlnk suggested showing on the settings screen, I
implemented display at the bottom of the WiFi Networks selection screen
(accessed via "File Transfer" > "Join a Network") since I think it makes
more sense there.
* Tested on my own device

---
### AI Usage
While CrossPoint doesn't have restrictions on AI tools in contributing,
please be transparent about their usage as it
helps set the right context for reviewers.
Did you use AI tools to help write this code? _**YES**_
---------
Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
## Summary
* This builds upon the helpful PR
https://github.com/crosspoint-reader/crosspoint-reader/pull/341, and
adds support for the setting to also apply to the XTC reader, which I
believed has just been missed and was not intentionally left out.
* XTC does not have chapter support yet, but it does skip 10 pages when
long-pressed, and so I think this is useful.
---
### AI Usage
Did you use AI tools to help write this code? No
~~Quick~~ fix for
https://github.com/daveallie/crosspoint-reader/issues/362
(this just applies to the chapter selection menu:)
~~If the orientation is portrait, hints as we know them make sense to
draw. If the orientation is inverted, we'd have to change the order of
the labels (along with everything's position), and if it's one of the
landscape choices, we'd have to render the text and buttons vertically.
All those other cases will be more complicated.~~
~~Punt on this for now by only rendering if portrait.~~
Update: this now draws the hints at the physical button position no
matter what the orientation is, by temporarily changing orientation to
portrait.
---------
Co-authored-by: Maeve Andrews <maeve@git.mail.maeveandrews.com>
Let's start small by showing the ALT text of IMG. This is rudimentary,
but avoids those otherwise completely blank chapters.
I feel we will need this even when we can render images if that
rendering takes >1s - I would then prefer rendering optional and showing
the ALT text first.
## Summary
* **What is the goal of this PR?**: Fix the bug I reported in
https://github.com/daveallie/crosspoint-reader/issues/292
* **What changes are included?**: Instead of silently dropping table
content in EPUBs., replace with an italicized '[Table omitted]' message
where tables appear.
## Additional Context
* Add any other information that might be helpful for the reviewer
(e.g., performance implications, potential risks,
specific areas to focus on).
---
### AI Usage
While CrossPoint doesn't have restrictions on AI tools in contributing,
please be transparent about their usage as it
helps set the right context for reviewers.
Did you use AI tools to help write this code? _**PARTIALLY **_
---------
Co-authored-by: Evan Fenner <evan@evanfenner.com>
Co-authored-by: Warp <agent@warp.dev>
Currently there is no visual indication whatsoever if something is in a
list. An `<li>` is essentially just another paragraph.
As a partial remedy for this, add a bullet character to the beginning of
`<li>` text blocks so that the user can see that they're list items.
This is incomplete in that an `<ol>` should also have a counter so that
its list items can get numbers instead of bullets (right now I don't
think we track if we're in a `<ul>` or an `<ol>` at all), but it's
strictly better than the current situation.
Co-authored-by: Maeve Andrews <maeve@git.mail.maeveandrews.com>
Currently, when Extra Paragraph Spacing is off, an em-space is added to
the beginning of each ParsedText even for blocks like headers that are
centered. This whitespace makes the centering slightly off. Change the
calculation here to only add the em-space for left/justified text.
Co-authored-by: Maeve Andrews <maeve@git.mail.maeveandrews.com>
## Summary
* **What is the goal of this PR?** Fix WiFi file transfer stability
issues (especially crashes during uploads) and improve upload speed via
WebSocket binary protocol. File transfers now don't really crash as
much, if they do it recovers and speed has gone form 50KB/s to 300+KB/s.
* **What changes are included?**
- **WebSocket upload support** - Adds WebSocket binary protocol for file
uploads, achieving faster speeds 335 KB/s vs HTTP multipart)
- **Watchdog stability fixes** - Adds `esp_task_wdt_reset()` calls
throughout upload path to prevent watchdog timeouts during:
- File creation (FAT allocation can be slow)
- SD card write operations
- HTTP header parsing
- WebSocket chunk processing
- **4KB write buffering** - Batches SD card writes to reduce I/O
overhead
- **WiFi health monitoring** - Detects WiFi disconnection in STA mode
and exits gracefully
- **Improved handleClient loop** - 500 iterations with periodic watchdog
resets and button checks for responsiveness
- **Progress bar improvements** - Fixed jumping/inaccurate progress by
capping local progress at 95% until server confirms completion
- **Exit button responsiveness** - Button now checked inside the
handleClient loop every 64 iterations
- **Reduced exit delays** - Decreased shutdown delays from ~850ms to
~140ms
**Files changed:**
- `platformio.ini` - Added WebSockets library dependency
- `CrossPointWebServer.cpp/h` - WebSocket server, upload buffering,
watchdog resets
- `CrossPointWebServerActivity.cpp` - WiFi monitoring, improved loop,
button handling
- `FilesPage.html` - WebSocket upload JavaScript with HTTP fallback
## Additional Context
- WebSocket uses 4KB chunks with backpressure management to prevent
ESP32 buffer overflow
- Falls back to HTTP automatically if WebSocket connection fails
- The main bottleneck now is SD card write speed (~44% of transfer
time), not WiFi
- STA mode was more prone to crashes than AP mode due to external
network factors; WiFi health monitoring helps detect and handle
disconnections gracefully
---
### AI Usage
Did you use AI tools to help write this code? _**YES**_ Claude did it
ALL, I have no idea what I am doing, but my books transfer fast now.
---------
Co-authored-by: Claude <noreply@anthropic.com>
## Summary
Adds a new "Long-press Chapter Skip" toggle in Settings to control
whether holding the side buttons skips chapters.
I kept accidentally triggering chapter skips while reading, which caused
me to lose my place in the middle of long chapters.
## Additional Context
* Add any other information that might be helpful for the reviewer
(e.g., performance implications, potential risks,
specific areas to focus on).
---
### AI Usage
While CrossPoint doesn't have restrictions on AI tools in contributing,
please be transparent about their usage as it
helps set the right context for reviewers.
Did you use AI tools to help write this code? _**PARTIALLY **_
## Summary
Adds define to omit optional fonts from the build. This reduces time to
flash from >31s to <13s. Useful for development that doesn't require
fonts. Addresses #193
Invoke it like this during development:
`PLATFORMIO_BUILD_FLAGS="-D OMIT_FONTS" pio run --target upload && pio
device monitor`
Changing the define causes `pio` to do a full rebuild (but it will be
quick if you keep the define).
---
### AI Usage
While CrossPoint doesn't have restrictions on AI tools in contributing,
please be transparent about their usage as it
helps set the right context for reviewers.
Did you use AI tools to help write this code? NO
## Summary
Skip BOM character (sometimes used in front of em-dashes) - they are not
part of the glyph set and would render `?` otherwise.
---
### AI Usage
Did you use AI tools to help write this code? _**YES**_
## Summary
* **What is the goal of this PR?**
Add support for reading plain text (.txt) files, enabling users to
browse, read, and track progress in TXT documents alongside existing
EPUB and XTC formats.
* **What changes are included?**
- New Txt library for loading and parsing plain text files
- New TxtReaderActivity with streaming page rendering using 8KB chunks
to handle large files without memory issues on ESP32-C3
- Page index caching system (index.bin) for instant re-open after sleep
or app restart
- Progress bar UI during initial file indexing (matching EPUB style)
- Word wrapping with proper UTF-8 support
- Cover image support for TXT files:
- Primary: image with same filename as TXT (e.g., book.jpg for book.txt)
- Fallback: cover.bmp/jpg/jpeg in the same folder
- JPG to BMP conversion using existing converter
- Sleep screen cover mode now works with TXT files
- File browser now shows .txt files
## Additional Context
* Add any other information that might be helpful for the reviewer
* Memory constraints: The streaming approach was necessary because
ESP32-C3 only has 320KB RAM. A 700KB TXT file cannot be loaded entirely
into memory, so we read 8KB chunks and build a page offset index
instead.
* Cache invalidation: The page index cache automatically invalidates
when file size, viewport width, or lines per page changes (e.g., font
size or orientation change).
* Performance: First open requires indexing (with progress bar),
subsequent opens load from cache instantly.
* Cover image format: PNG is detected but not supported for conversion
(no PNG decoder available). Only BMP and JPG/JPEG work.
## Summary
* **What is the goal of this PR?** (e.g., Fixes a bug in the user
authentication module,
Display the book cover image in the **"Continue Reading"** card on the
home screen, with fast navigation using framebuffer caching.
* **What changes are included?**
- Display book cover image in the "Continue Reading" card on home screen
- Load cover from cached BMP (same as sleep screen cover)
- Add framebuffer store/restore functions (`copyStoredBwBuffer`,
`freeStoredBwBuffer`) for fast navigation after initial render
- Fix `drawBitmap` scaling bug: apply scale to offset only, not to base
coordinates
- Add white text boxes behind title/author/continue reading label for
readability on cover
- Support both EPUB and XTC file cover images
- Increase HomeActivity task stack size from 2048 to 4096 for cover
image rendering
## Additional Context
* Add any other information that might be helpful for the reviewer
(e.g., performance implications, potential risks, specific areas to
focus on).
- Performance: First render loads cover from SD card (~800ms),
subsequent navigation uses cached framebuffer (~instant)
- Memory: Framebuffer cache uses ~48KB (6 chunks × 8KB) while on home
screen, freed on exit
- Fallback: If cover image is not available, falls back to standard
text-only display
- The `drawBitmap` fix corrects a bug where screenY = (y + offset) scale
was incorrectly scaling the base coordinates. Now correctly uses screenY
= y + (offset scale)