[ENVIRONMENT] PyTorch on Windows Requires Python 3.12 — Python 3.13 Causes Installation Failure

[jieyao-MilestoneHub]

When setting up the environment on Windows, GPU inference works correctly at first.
However, after running:

uv sync --extra dev

uv switches to:

Using CPython 3.13.3

Root Cause

× No solution found when resolving dependencies:
╰─▶ Because only the following versions of torch are available:
        torch==0.1
        torch==0.1.6.post17
        torch==0.1.6.post20
        torch==0.1.6.post22
        torch==0.1.7.post2
        torch==0.1.8.post1
        torch==0.1.9.post1
        torch==0.1.9.post2
        torch==0.1.10.post1
        torch==0.1.11.post4
        torch==0.1.11.post5
        torch==0.1.12.post1
        torch==0.1.12.post2
        torch==0.2.0.post1
        torch==0.2.0.post2
        torch==0.2.0.post3
        torch==0.3.0
        torch==0.3.0.post2
        torch==0.3.0.post3
        torch==0.3.0.post4
        torch==0.3.1
        torch==0.4.0
        torch==0.4.1
        torch==1.11.0
        torch==1.12.0
        torch==1.12.1
        torch==1.13.0
        torch==1.13.1
        torch==2.0.0
        torch==2.0.1
        torch==2.1.0+cu121
        torch==2.1.1+cu121
        torch==2.1.2+cu121
        torch==2.2.0+cu121
        torch==2.2.1+cu121
        torch==2.2.2+cu121
        torch==2.3.0+cu121
        torch==2.3.1+cu121
        torch==2.4.0+cu121
        torch==2.4.1+cu121
        torch==2.5.0+cu121
        torch==2.5.1+cu121
    and torch<=2.4.1+cu121 has no wheels with a matching Python ABI tag (e.g., `cp313`),
    we can conclude that torch<=2.4.1+cu121 cannot be used.
    And because torch>=2.5.0+cu121 has no wheels with a matching platform tag (e.g., `win_amd64`)
    and you require torch, we can conclude that your requirements are unsatisfiable.

    hint: You require CPython 3.13 (`cp313`), but we only found wheels for `torch` (v2.4.1+cu121) with
    the following Python ABI tags: `cp38`, `cp39`, `cp310`, `cp311`, `cp312`

    hint: Wheels are available for `torch` (v2.5.1+cu121) on the following platform: `linux_x86_64`

Proposed solution

• Pin Python to 3.12 in pyproject.toml:

requires-python = "==3.12.*"

• Update README to note:

Windows users must use Python 3.12, since PyTorch does not yet support Python 3.13 on Windows.

Downgrading to Python 3.12 resolves the issue and allows PyTorch + CUDA to install correctly.