Add horizontal long strip reading modes

[luisfilipemendesnogueira]

Summary

Adds two horizontal long strip reading modes to the reader:

• Horizontal long strip (right to left)
• Horizontal long strip (left to right)

This updates the webtoon viewer to support horizontal scrolling, adjusts page sizing and image scaling for the horizontal axis

Partially addresses #2023.

What changed

• Added two new reading mode entries and labels for horizontal long strip LTR/RTL
• Added icons for both horizontal modes
• Updated WebtoonViewer to support horizontal orientation
• Adjusted webtoon page holder sizing and image fit behavior for horizontal reading
• Updated reader app bars so chapter navigation respects horizontal RTL mode

Scope

This PR only implements the horizontal long strip reading modes for phones / general horizontal scrolling behavior.

It does not implement the tablet-specific behavior mentioned in #2023

Testing

Tested manually by:

• Opening chapters in both horizontal long strip modes
• Verifying left-to-right and right-to-left scrolling behavior
• Verifying tap navigation and chapter navigation direction
• Verifying image scaling/layout behavior in horizontal mode

Videos

mihon-test.mp4

[MajorTanya]

Good luck with those absurd 30,000x2,000 px images per "page" on this one

[luisfilipemendesnogueira]

Good luck with those absurd 30,000x2,000 px images per "page" on this one

@MajorTanya I'm kinda new to this thing, could you explain your point better to me? So I can study and learn more about this in order to fix it

[MajorTanya]

Good luck with those absurd 30,000x2,000 px images per "page" on this one

@MajorTanya I'm kinda new to this thing, could you explain your point better to me? So I can study and learn more about this in order to fix it

Some people/sources provide webtoon/manhwa images as very tall images (the example I gave above is a real example I saw just the other week). That'd be a nightmare on a horizontal continuous reading mode.

But it was more generally just a joke and not something serious about the PR itself. 👍

[luisfilipemendesnogueira]

Some people/sources provide webtoon/manhwa images as very tall images (the example I gave above is a real example I saw just the other week). That'd be a nightmare on a horizontal continuous reading mode.

But it was more generally just a joke and not something serious about the PR itself. 👍

Fair enough

I was mainly thinking of this mode being used for manga/comics, especially for cases where double-page spreads are split in half by the source. I used the webtoon naming in the code mostly for consistency with the existing vertical long strip mode, since it's already referred to as webtoon throughout the code.