Add multiline Text Shape with wrap, shrink, and surface following

[rhys100]

Summary

• Multiline Text Shape support for issues [Feature Request]Multiple Lines for Text Shape & More #1095 / Add Multiple Lines of Text #2086: Enter inserts real line breaks.
• Auto wrap to a width, optional wrap height, and auto shrink font size to fit the box.
• Multiline surface text follows the mesh per line (parallel slice contours + sample_slice), not a flat stamp.
• Persist newlines, line/char gap, and wrap settings in 3MF.

What changed

• Emboss::apply_text_wrap / fit_text_to_box for layout preprocess
• GenerateTextJob baked layout for horizontal multiline; surface multiline uses create_text_lines + sample_slice
• Text tool UI: Auto wrap, Auto shrink, Wrap width / height, Line gap
• Font version bumped to 2.7

Test plan

• Type multiline text with Enter — lines stack on flat/horizontal text
• Enable Auto wrap + set Wrap width — long text wraps onto new lines
• Enable Auto shrink + Wrap width/height — font size reduces to fit the box
• Place multiline text on a curved surface — each line follows the surface
• Save / reload 3MF — newlines, wrap settings, and line gap survive
• Confirm single-line text behaviour is unchanged

Fixes #1095
Related #2086

[Haidiye00]

Hello, please use GIF software to record the modified effect. Thank you

[Haidiye00]

Hello, it is recommended to combine two patches into one patch. Thank you

[rhys100]

Thanks for the review notes — both addressed:

1. Combined into one commit (force-pushed).
2. Demo GIF of the updated Text Shape behaviour:

https://raw.githubusercontent.com/rhys100/BambuStudio/feature/text-shape-multiline/pr-media/pr-11592-text-shape-demo.gif

Also in the branch at pr-media/pr-11592-text-shape-demo.gif.

It shows:

• Enter / multiline input
• Auto wrap into a width box
• Auto shrink to fit height
• Multiline text following a curved surface

Happy to replace this with a live Bambu Studio screen recording if you prefer that format.