Merged upstream changes while preserving Korean-specific customizations:
- Korean UI translations in SettingsActivity
- Korean fonts (Eulyoo 14pt, Pretendard UI)
- 1-bit Atkinson dithering for fast home screen rendering
- Cover image and TXT file support

Key upstream features merged:
- Fix BMP rendering gamma/brightness (crosspoint-reader#302)
- Different .bmp for cropped covers (crosspoint-reader#330)
- Handle EPUB 3 TOC to spine mapping (crosspoint-reader#332)
- Wi-Fi Selection on Calibre Library launch (crosspoint-reader#313)
- Increase home activity stack size (crosspoint-reader#333)

Resolved conflicts:
- BitmapHelpers.h/cpp: Use upstream shared dithering functions
- JpegToBmpConverter.cpp: Keep Korean 1-bit Atkinson1BitDitherer
- SettingsActivity.cpp: Add new settings in Korean
- Epub.h: Keep both crop and thumb functions
- platformio.ini: Set version to 0.13.1-ko.0

…crosspoint-reader#332)

## Summary

- Nav file in EPUB 3 file is a HTML file with relative hrefs
- If this file exists anywhere but in the same location as the
content.opf file, navigating in the book will fail
- Bump the book cache version to rebuild potentially broken books

## Additional Context

- Fixes crosspoint-reader#264

---

### 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
- [ ] Partially
- [x] No

commit 21277e0
Author: Luke Stein <[email protected]>
Date:   Thu Jan 15 07:27:17 2026 -0500

    docs: Update User Guide to reflect release 0.14.0 (crosspoint-reader#376)

commit 4eef2b5
Author: Luke Stein <[email protected]>
Date:   Thu Jan 15 07:26:39 2026 -0500

    feat: Add MAC address display to WiFi Networks screen (crosspoint-reader#381)

    ## Summary

    * Implements crosspoint-reader#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

    ![IMG_2873](https://github.com/user-attachments/assets/b82a20dc-41a0-4b21-81f1-20876aa2c6b0)

    ---

    ### 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] <[email protected]>

commit 5a55fa1
Author: Nathan James <[email protected]>
Date:   Thu Jan 15 12:25:18 2026 +0000

    fix: also apply longPressChapterSkip setting to xtc reader (crosspoint-reader#378)

    ## Summary

    * This builds upon the helpful PR
    crosspoint-reader#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

commit c98ba14
Author: Maeve Andrews <[email protected]>
Date:   Thu Jan 15 06:23:36 2026 -0600

    fix: draw button hints correctly if orientation is not portrait (crosspoint-reader#363)

    ~~Quick~~ fix for
    crosspoint-reader#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 <[email protected]>

commit c1c94c0
Author: Jonas Diemer <[email protected]>
Date:   Thu Jan 15 13:21:46 2026 +0100

    Feature: Show img alt text (crosspoint-reader#168)

    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.

commit eb84bce
Author: Dave Allie <[email protected]>
Date:   Thu Jan 15 02:22:38 2026 +1100

    chore: Pin links2004/WebSockets version

commit d45f355
Author: efenner <[email protected]>
Date:   Thu Jan 15 05:14:59 2026 -0700

    feat: Add EPUB table omitted placeholder (crosspoint-reader#372)

    ## Summary

    * **What is the goal of this PR?**: Fix the bug I reported in
    crosspoint-reader#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 <[email protected]>
    Co-authored-by: Warp <[email protected]>

commit 56ec3df
Author: Dave Allie <[email protected]>
Date:   Thu Jan 15 01:01:47 2026 +1100

    chore: Cut release 0.14.0

commit e517945
Author: Maeve Andrews <[email protected]>
Date:   Wed Jan 14 06:23:03 2026 -0600

    Add a bullet to the beginning of any <li> (crosspoint-reader#368)

    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 <[email protected]>

commit 4892208
Author: Maeve Andrews <[email protected]>
Date:   Wed Jan 14 06:21:48 2026 -0600

    Only indent paragraphs for justify/left-align (crosspoint-reader#367)

    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 <[email protected]>

commit 3ee10b3
Author: Dave Allie <[email protected]>
Date:   Wed Jan 14 23:14:00 2026 +1100

    Update OTA updater URL

commit a946c83
Author: swwilshub <[email protected]>
Date:   Wed Jan 14 12:11:28 2026 +0000

    Turbocharge WiFi uploads with WebSocket + watchdog stability (crosspoint-reader#364)

    ## 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 <[email protected]>

commit 847786e
Author: Justin Mitchell <[email protected]>
Date:   Wed Jan 14 06:54:14 2026 -0500

    Fixes issue with Calibre web expecting SSL (crosspoint-reader#347)

    http urls now work with Calibre web

    ---------

    Co-authored-by: Dave Allie <[email protected]>

commit c2fb8ce
Author: Luke Stein <[email protected]>
Date:   Wed Jan 14 06:48:43 2026 -0500

    Update User Guide to reflect release 0.13.1 (crosspoint-reader#337)

    Please note I have not tested the Calibre features and am not yet in a
    position to offer detailed documentation of how they work.

commit ed05554
Author: Armando Cerna <[email protected]>
Date:   Wed Jan 14 06:47:24 2026 -0500

    feat: Add setting to toggle long-press chapter skip (crosspoint-reader#341)

    ## 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 **_

commit 9a9dc04
Author: Jonas Diemer <[email protected]>
Date:   Wed Jan 14 12:40:40 2026 +0100

    ifdef around optional fonts to reduce flash size/time. (crosspoint-reader#339)

    ## 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 crosspoint-reader#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

commit 1c027ce
Author: Jonas Diemer <[email protected]>
Date:   Wed Jan 14 12:38:30 2026 +0100

    Skip BOM character (sometimes used in front of em-dashes) (crosspoint-reader#340)

    ## 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**_

commit 49f97b6
Author: Eunchurn Park <[email protected]>
Date:   Wed Jan 14 19:36:40 2026 +0900

    Add TXT file reader support (crosspoint-reader#240)

    ## 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.

commit 14643d0
Author: Dave Allie <[email protected]>
Date:   Wed Jan 14 21:19:12 2026 +1100

    Move string helpers out of HomeActivity into StringUtils

commit fecd184
Author: Eunchurn Park <[email protected]>
Date:   Wed Jan 14 19:24:02 2026 +0900

    Add cover image display in *Continue Reading* card with framebuffer caching (crosspoint-reader#200)

    ## 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)

commit 2040e08
Author: Will Morrow <[email protected]>
Date:   Wed Jan 14 05:05:08 2026 -0500

    Ensure new custom sleep image every time (crosspoint-reader#300)

    When picking a random sleep image from a set of custom images, compare
    the randomly chosen index against a cached value in settings. If the
    value matches, use the next image (rolling over if it's the last image).
    Cache the chosen image index to settings in either case.

    ## Summary

    Implements a tweak on the custom sleep image feature that ensures that
    the user gets a new image every time the device goes to sleep.
    This change adds a new setting (perhaps there's a better place to cache
    this?) that stores the most recently used file index. During picking the
    random image index, we compare this against the random index and choose
    the next one (modulo the number of image files) if it matches, ensuring
    we get a new image.

    ## Additional Context

    As mentioned, I used settings to cache this value since it is a
    persisted store, perhaps that's overkill. Open to suggestions on if
    there's a better way.

commit 65d2391
Author: Andrew Brandt <[email protected]>
Date:   Wed Jan 14 04:04:02 2026 -0600

    ci: add PR format check workflow (crosspoint-reader#328)

    **Description**:

    Add a new workflow to check the PR formatting to ensure consistency on
    PR titles. We can also use this for semantic release versioning later,
    if we so desire.

    **Related Issue(s)**:

    Implements first portion of crosspoint-reader#327

    ---------

    Signed-off-by: Andrew Brandt <[email protected]>

commit 52995fa
Author: Dave Allie <[email protected]>
Date:   Tue Jan 13 02:09:39 2026 +1100

    chore: Cut release 0.13.1

commit d4f8eda
Author: Dave Allie <[email protected]>
Date:   Tue Jan 13 01:09:06 2026 +1000

    fix: Increase home activity stack size (crosspoint-reader#333)

    ## Summary

    * fix: Increase home activity stack size

    ## Additional Context

    * Home activity can crash occasionally depending on book

    ---

    ### 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

commit 33b8fa0
Author: Dave Allie <[email protected]>
Date:   Tue Jan 13 00:56:21 2026 +1100

    chore: Cut release 0.13.0

commit 16c760b
Author: Dave Allie <[email protected]>
Date:   Tue Jan 13 00:58:43 2026 +1100

    copy: Tweak pull request template wording

commit 8f3df7e
Author: Dave Allie <[email protected]>
Date:   Mon Jan 12 23:57:34 2026 +1000

    fix: Handle EPUB 3 TOC to spine mapping when nav file in subdirectory (crosspoint-reader#332)

    ## Summary

    - Nav file in EPUB 3 file is a HTML file with relative hrefs
    - If this file exists anywhere but in the same location as the
    content.opf file, navigating in the book will fail
    - Bump the book cache version to rebuild potentially broken books

    ## Additional Context

    - Fixes crosspoint-reader#264

    ---

    ### 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
    - [ ] Partially
    - [x] No

commit 0165fab
Author: Jonas Diemer <[email protected]>
Date:   Mon Jan 12 12:36:19 2026 +0100

    Fix BMP rendering gamma/brightness (crosspoint-reader#302)

    1. Refactor Bitmap.cpp/h to expose the options for FloydSteinberg and
    brightness/gamma correction at runtime
    2. Fine-tune the thresholds for Floyd Steiberg and simple quantization
    to better match the display's colors

    Turns out that 2 is enough to make the images render properly, so the
    brightness boost and gamma adjustment doesn't seem necessary currently
    (at least for my test image).

commit 66b100c
Author: danoob <[email protected]>
Date:   Mon Jan 12 17:49:42 2026 +0700

    fix: Wi-Fi Selection on Calibre Library launch (crosspoint-reader#313)

    ## Summary

    * **What is the goal of this PR?**
    Fixes the Wi-Fi connection issue when launching the Calibre Library
    (OPDS browser). The previous implementation always attempted to connect
    using the first saved WiFi credential, which caused connection failures
    when users were in locations where only other saved networks (not the
    first one) were available. Now, the activity launches a WiFi selection
    screen allowing users to choose from available networks.

    * **What changes are included?**

    ## Additional Context
    **Bug Fixed**: Previously, the code used `credentials[0]` (always the
    first saved WiFi), so users in areas with only their secondary/tertiary
    saved networks available could never connect.

    ---------

    Co-authored-by: danoooob <[email protected]>

commit 41bda43
Author: Andrew Brandt <[email protected]>
Date:   Mon Jan 12 04:37:23 2026 -0600

    chore: update formatting in github workflows (crosspoint-reader#320)

    **Description**:

    The purpose of this change is to modify the spacing in the
    `.github/workflow` files to ensure consistency.

    **Related Issue(s)**:

    Implements crosspoint-reader#319

    Signed-off-by: Andrew Brandt <[email protected]>

commit 82f21f3
Author: Dave Allie <[email protected]>
Date:   Mon Jan 12 21:35:18 2026 +1100

    Add AI usage question to the PR template

commit a9242fe
Author: Jonas Diemer <[email protected]>
Date:   Mon Jan 12 10:55:47 2026 +0100

    Generate different .bmp for cropped covers so settings have effect. (crosspoint-reader#330)

    Addresses
    crosspoint-reader#225 (comment)

commit 88d0d90
Author: Jonas Diemer <[email protected]>
Date:   Mon Jan 12 10:53:58 2026 +0100

    Add option to hide battery percentage. (crosspoint-reader#297)

    with option to always hide or hide in reader only.

    Co-authored-by: Dave Allie <[email protected]>

commit 97c4871
Author: David Fischer <[email protected]>
Date:   Mon Jan 12 10:07:26 2026 +0100

    Add page turn on power button press (crosspoint-reader#286)

    ## Summary

    * **What is the goal of this PR?**
    * This PR adds a setting to (additionally) map the forward page turn
    onto the powerbutton when in `EPUBReaderActivity` and powerbutton short
    press is not mapped to sleep mode. I find the powerbutton to be exactly
    where my thumb is while reading so it is very convenient to map the
    forwardpage turn to that. Maybe Im not alone with this ^^
    * **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).

commit 66811bf
Author: Seth <[email protected]>
Date:   Mon Jan 12 00:59:02 2026 -0800

    Add navigation hints to ChapterSelectionActivities (crosspoint-reader#294)

    ## Summary

    Add navigation hints to Chapter Select - crosspoint-reader#190

    ### Before

    ![Mi 11X_20260108_214114_lmc_8
    4](https://github.com/user-attachments/assets/45031d21-2c6c-4b7d-a5cc-6ad111bf5a70)

    ### After
    ![Mi 11X_20260108_213803_lmc_8
    4](https://github.com/user-attachments/assets/1fa4ef22-63e4-4adb-8fc5-5fb8c7fa79fa)

commit 8728701
Author: Samuel Carpentier <[email protected]>
Date:   Mon Jan 12 17:58:08 2026 +0900

    Updated user guide (sleep screens list) (crosspoint-reader#293)

    ## Summary

    Updated sleep screens list by adding the newly available "Blank" option

…crosspoint-reader#332)

## Summary

- Nav file in EPUB 3 file is a HTML file with relative hrefs
- If this file exists anywhere but in the same location as the
content.opf file, navigating in the book will fail
- Bump the book cache version to rebuild potentially broken books

## Additional Context

- Fixes crosspoint-reader#264

---

### 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
- [ ] Partially
- [x] No

…crosspoint-reader#332)

## Summary

- Nav file in EPUB 3 file is a HTML file with relative hrefs
- If this file exists anywhere but in the same location as the
content.opf file, navigating in the book will fail
- Bump the book cache version to rebuild potentially broken books

## Additional Context

- Fixes crosspoint-reader#264

---

### 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
- [ ] Partially
- [x] No