Latex compilation and svg error

### Bug - Part 1
Relates to #2440. A few days ago i stumbled upon a strange bug when compiling a latex file. The error ocurrs in the module `utils/tex_file_writing.py` in the function `full_tex_to_svg()`, it pops out from the constructor of `Tex`. Specifically it is the line 108
```python
process = subprocess.run(
[
compiler,
*(['-no-pdf'] if compiler == "xelatex" else []),
"-interaction=batchmode",
"-halt-on-error",
f"-output-directory={temp_dir}",
tex_path
],
capture_output=True,
text=True
)
```
When executing this process it fails miserably despite previously being able to write the complete latex file:
```python
tex_path.write_text(full_tex) # Writes the file properly
```
Meaning that both `tex_path` and `temp_dir` (which relates to the declaration `tex_path = temp_dir / "working.tex"`) are correct paths. I debugged it a little for a while but it didn't make much sense and it also didn't help that the error message was not explicit at all.

### Solution

A few days later I now come back to the issue and the problem was simply that python or latex was getting confused with the directories. Replacing the command with
```python
process = subprocess.run(
[
compiler,
*(['-no-pdf'] if compiler == "xelatex" else []),
"-interaction=batchmode",
"-halt-on-error",
"working.tex"
],
capture_output=True,
text=True,
cwd=temp_dir
)
```
Fixed it for me.

python version: 3.13.12
manimgl version: 1.7.2
Latex:
pdfTeX 3.141592653-2.6-1.40.29 (TeX Live 2026)

### Bug - Part 2

After having solved the latex compilation issue (so the only change I made to my local copy of manim is the above substitution), now I run into the issue of an svg not creating properly. I haven't looked exhaustively into the issue but upon a quick inspection while debugging I noticed the first time the function `latex_to_svg()` runs it outputs a non-empty svg xml. The first time it runs is inside the parent constructor of `Tex()` in line 69:
```python
super().__init__(
tex_string,
use_labelled_svg=use_labelled_svg,
isolate=isolate,
**kwargs
)
```
ends up calling
```python
def get_svg_string_by_content(self, content: str) -> str:
return latex_to_svg(content, self.template, self.additional_preamble, short_tex=self.tex_string)
```
However right after when running `get_tex_mob_scale_factor()` the call `latex_to_svg("0", show_message_during_execution=False)` gives an empty svg. This is:
```python
super().__init__(
tex_string,
use_labelled_svg=use_labelled_svg,
isolate=isolate,
**kwargs
)

self.set_color_by_tex_to_color_map(self.tex_to_color_map)
self.scale(get_tex_mob_scale_factor() * font_size)
```
that last line calls:
```python
@lru_cache(maxsize=1)
def get_tex_mob_scale_factor() -> float:
# Render a reference "0" and calibrate so that font_size_for_unit_height
# gives a height of 1 manim unit. Compensates for platform dvisvgm differences.
font_size_for_unit_height = manim_config.tex.font_size_for_unit_height

svg_string = latex_to_svg("0", show_message_during_execution=False)

svg_height = get_svg_content_height(svg_string)
return 1.0 / (font_size_for_unit_height * svg_height)
```
and `svg_string` ends up being an xml containing an empty svg.
Another weird thing is the following: when `latex_to_svg("0", show_message_during_execution=False)` gets called it leads to the second time of `full_tex_to_svg()` being called. The first time `full_tex_to_svg()` is called is to create my latex text and this second time it should create a tex document with a "0". However, the execution seems to completely skip the second time `full_tex_to_svg()` is called because the debugger does not stop at the breakpoints the second time but the first time it does.
I'm fairly new to this so forgive me if I'm making some sort of mistake or misunderstanding but I feel like it is a strange error.

python version: 3.13.12
manimgl version: 1.7.2
Latex:
pdfTeX 3.141592653-2.6-1.40.29 (TeX Live 2026)
dvisvgm version: 3.6

Note: This all happens when just calling the `Tex` constructor.
PS: Windows 11 OS