[Code scan] HTI modules fail to import because dpti.hti imports re.T

Source: Codex global repository scan of deepmodeling/dpti at commit b719828e7eeb571bd26411430197cd74ea78e38c.
Project: https://github.com/orgs/deepmodeling/projects/27

Problem
`dpti.hti` imports `T` from Python's `re` module, but current Python versions do not expose that symbol. This makes `import dpti.hti` fail at module import time, and any module that imports it, such as `dpti.hti_ice`, fails before its CLI or APIs can run.

Code references
https://github.com/deepmodeling/dpti/blob/b719828e7eeb571bd26411430197cd74ea78e38c/dpti/hti.py#L4
https://github.com/deepmodeling/dpti/blob/b719828e7eeb571bd26411430197cd74ea78e38c/dpti/hti_ice.py#L8

Reproduction
Run:

```bash
python -c "import dpti.hti"
```

Observed result:
`ImportError: cannot import name 'T' from 're'`.

Expected result
The HTI modules should import cleanly. The unused `from re import T` line should be removed or replaced with a valid import if it was intended for something else.

Start at dpti/hti.py line 4 and dpti/hti_ice.py line 8, then run python -c "import dpti.hti" to reproduce the ImportError. Remove or correct the invalid re import, and verify that the HTI modules import cleanly without the reported failure.

Written by the indexing model from the issue text.