fix: Ender-3 V2 / S1 DACAI LCD compatibility with custom UIs, improve LCD READMEs

[vlad-the-compiler]

Description

This PR fixes the private asset bundle folder for DACAI LCDs, making them compatible with custom UIs.

The following modifications have been made to the DACAI private folder:

• config.txt has been adjusted to allow the font sizes to match the DWIN display
  • Sourced from official Creality firmware
  • Text no longer draws out-of-bounds and now properly clears the background when it changes
• truefont/font.ttf has been changed from SimSun (serif) to SimHei (sans-serif)
  • Sourced from official Creality firmware
  • Font has been edited to include the Marlin Icons, MarlinUI now draws the Forward, Back, Degree, Feed Rate, and Folder font icons correctly
• The complete DWIN_SET graphics asset bundle has been converted into DACAI ZICO format
  • This brings the updated icons set to DACAI displays, allowing for custom UIs to render all icons correctly

Additionally, the README.md files for Ender-3 S1 and Ender-3 V2 LCD Files folders have been updated as follows:

• Ender-3 V2 LCD Files/README.md:
  • Now includes a full guide to identify all 4 types of display units (DWIN, DACAI, SYNWIT / VIEWE, TJC), along with their known specs
  • Includes a per-display UI compatibility list
  • Separate instructions have been added for flashing DWIN and DACAI LCDs
• The Ender-3 S1 LCD Files/README.md has been updated to a general notice regarding the different types of display, redirecting to the comprehensive Ender-3 V2 display family readme mentioned above

Benefits

The DACAI LCD files update ensures this display unit now works properly with all Creality UI-based custom interfaces, and with MarlinUI. Text and icons are now displayed properly.
Please note that MarlinUI in Landscape is still not possible on this display, as the DACAI unit appears to omit the API for display rotation.

The updated README.md files provide more information about the different types of displays, their compatibility with the different UIs, and ways to update them (where currently available).

Related Issues

Partially fixes MarlinFirmware/Marlin#25195
Rendering issues are resolved, Landscape is incompatible due to display API limitations or currently unknown opcodes.

[thinkyhead]

Some of the JPGs are increasing in size although they are not changing graphically. @ellensp recently compressed the images with JPEG.io so any images that are increasing in size should probably be run through that filter again.

[mriscoc]

Currently there are two SYNWIT/VIEWE display versions.
HAS_GCODE_PREVIEW must be disabled to use ProUI with SYNWIT/VIEWE
TJC displays can be used with ProUI, but no values are shown in the mesh viewer due to missing small fonts.

[ellensp]

@mriscoc any chance you could update your page so the images are clickable to a larger image, not all of us have 20/20 vision...
Or just a link to a high res image...

[EvilGremlin]

I think we should pull this page both into general marlin docs and into creality conf directory.
Also move screen assets up from e3v2 dir.

[mriscoc]

@mriscoc any chance you could update your page so the images are clickable to a larger image, not all of us have 20/20 vision... Or just a link to a high res image...

I will try to do it, but users give me low-res images.

[EvilGremlin]

I think @InsanityAutomation can make decent photos for all of them

[mriscoc]

@mriscoc any chance you could update your page so the images are clickable to a larger image,

Done.