Loading in venv no longer works

### Custom Node Testing

- [x] I have tried disabling custom nodes and the issue persists (see [how to disable custom nodes](https://docs.comfy.org/troubleshooting/custom-node-issues#step-1%3A-test-with-all-custom-nodes-disabled) if you need help)

### Expected Behavior

Loading ComfyUI in the venv I prepared for it.

### Actual Behavior

It tells me sqlalchemy is not installed.

### Steps to Reproduce

I have a custom start script for this, which worked until yesterday with my existing and long running install. Still no idea why that one stopped working, as laid out in this report: [https://github.com/Comfy-Org/ComfyUI/issues/14694](https://github.com/Comfy-Org/ComfyUI/issues/14694)
But because I need it, and I don't expect a quick solution to that one, and I felt like doing some spring cleaning anyway I decided to just do a fresh install in a fresh venv with a newer Python version and only install the addons I actually need now.
So I did that, and now the script to run it in the venv yields the above result.
If I run the main.py script directly it works, but then it's not running in venv, which is not ideal.
Custom start script for running in venv is thus:
```
#!/bin/bash

# Activate virtual environment
source ComfyUI/bin/activate

# Verify the venv is active (optional - for debugging)
echo "Using Python from: $(which python)"
echo "Python version: $(python --version)"

# Change to the main directory before running
cd ComfyUI/ComfyUI

# Run the Python program
python main.py --port=7860 --enable-manager --enable-cors-header '*' --listen #--disable-dynamic-vram #--highvram #--disable-smart-memory
```
Ignore the disabled options, I've just been experimenting.

### Debug Logs

```powershell
'/home/username/Stable/ComfyUIStart.sh'
Using Python from: /home/username/Stable/ComfyUI/bin/python
Python version: Python 3.12.6
Traceback (most recent call last):
File "/home/username/Stable/ComfyUI/ComfyUI/main.py", line 22, in
from app.assets.seeder import asset_seeder
File "/home/username/Stable/ComfyUI/ComfyUI/app/assets/seeder.py", line 11, in
from app.assets.scanner import (
File "/home/username/Stable/ComfyUI/ComfyUI/app/assets/scanner.py", line 7, in
from app.assets.database.queries import (
File "/home/username/Stable/ComfyUI/ComfyUI/app/assets/database/queries/__init__.py", line 1, in
from app.assets.database.queries.asset import (
File "/home/username/Stable/ComfyUI/ComfyUI/app/assets/database/queries/asset.py", line 1, in
import sqlalchemy as sa
ModuleNotFoundError: No module named 'sqlalchemy'
```

### Other

Yes I am aware of https://github.com/Comfy-Org/ComfyUI/issues/14172 But that makes no mention of venv, and I am running this on linux, not windows.

Start by running the reported ComfyUIStart.sh script in the fresh virtual environment and follow the import chain from main.py through app/assets/seeder.py, app/assets/scanner.py, and app/assets/database/queries/asset.py. Check why the venv cannot import sqlalchemy while direct execution works; done means the venv launch reaches normal startup without the ModuleNotFoundError.

Written by the indexing model from the issue text.