chore: 添加虚拟环境到仓库

- 添加 backend_service/venv 虚拟环境
- 包含所有Python依赖包
- 注意：虚拟环境约393MB，包含12655个文件

backend_service/venv/lib/python3.13/site-packages/sympy/physics/matrices.py

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+"""Known matrices related to physics"""
+
+from sympy.core.numbers import I
+from sympy.matrices.dense import MutableDenseMatrix as Matrix
+from sympy.utilities.decorator import deprecated
+
+
+def msigma(i):
+    r"""Returns a Pauli matrix `\sigma_i` with `i=1,2,3`.
+
+    References
+    ==========
+
+    .. [1] https://en.wikipedia.org/wiki/Pauli_matrices
+
+    Examples
+    ========
+
+    >>> from sympy.physics.matrices import msigma
+    >>> msigma(1)
+    Matrix([
+    [0, 1],
+    [1, 0]])
+    """
+    if i == 1:
+        mat = (
+            (0, 1),
+            (1, 0)
+        )
+    elif i == 2:
+        mat = (
+            (0, -I),
+            (I, 0)
+        )
+    elif i == 3:
+        mat = (
+            (1, 0),
+            (0, -1)
+        )
+    else:
+        raise IndexError("Invalid Pauli index")
+    return Matrix(mat)
+
+
+def pat_matrix(m, dx, dy, dz):
+    """Returns the Parallel Axis Theorem matrix to translate the inertia
+    matrix a distance of `(dx, dy, dz)` for a body of mass m.
+
+    Examples
+    ========
+
+    To translate a body having a mass of 2 units a distance of 1 unit along
+    the `x`-axis we get:
+
+    >>> from sympy.physics.matrices import pat_matrix
+    >>> pat_matrix(2, 1, 0, 0)
+    Matrix([
+    [0, 0, 0],
+    [0, 2, 0],
+    [0, 0, 2]])
+
+    """
+    dxdy = -dx*dy
+    dydz = -dy*dz
+    dzdx = -dz*dx
+    dxdx = dx**2
+    dydy = dy**2
+    dzdz = dz**2
+    mat = ((dydy + dzdz, dxdy, dzdx),
+           (dxdy, dxdx + dzdz, dydz),
+           (dzdx, dydz, dydy + dxdx))
+    return m*Matrix(mat)
+
+
+def mgamma(mu, lower=False):
+    r"""Returns a Dirac gamma matrix `\gamma^\mu` in the standard
+    (Dirac) representation.
+
+    Explanation
+    ===========
+
+    If you want `\gamma_\mu`, use ``gamma(mu, True)``.
+
+    We use a convention:
+
+    `\gamma^5 = i \cdot \gamma^0 \cdot \gamma^1 \cdot \gamma^2 \cdot \gamma^3`
+
+    `\gamma_5 = i \cdot \gamma_0 \cdot \gamma_1 \cdot \gamma_2 \cdot \gamma_3 = - \gamma^5`
+
+    References
+    ==========
+
+    .. [1] https://en.wikipedia.org/wiki/Gamma_matrices
+
+    Examples
+    ========
+
+    >>> from sympy.physics.matrices import mgamma
+    >>> mgamma(1)
+    Matrix([
+    [ 0,  0, 0, 1],
+    [ 0,  0, 1, 0],
+    [ 0, -1, 0, 0],
+    [-1,  0, 0, 0]])
+    """
+    if mu not in (0, 1, 2, 3, 5):
+        raise IndexError("Invalid Dirac index")
+    if mu == 0:
+        mat = (
+            (1, 0, 0, 0),
+            (0, 1, 0, 0),
+            (0, 0, -1, 0),
+            (0, 0, 0, -1)
+        )
+    elif mu == 1:
+        mat = (
+            (0, 0, 0, 1),
+            (0, 0, 1, 0),
+            (0, -1, 0, 0),
+            (-1, 0, 0, 0)
+        )
+    elif mu == 2:
+        mat = (
+            (0, 0, 0, -I),
+            (0, 0, I, 0),
+            (0, I, 0, 0),
+            (-I, 0, 0, 0)
+        )
+    elif mu == 3:
+        mat = (
+            (0, 0, 1, 0),
+            (0, 0, 0, -1),
+            (-1, 0, 0, 0),
+            (0, 1, 0, 0)
+        )
+    elif mu == 5:
+        mat = (
+            (0, 0, 1, 0),
+            (0, 0, 0, 1),
+            (1, 0, 0, 0),
+            (0, 1, 0, 0)
+        )
+    m = Matrix(mat)
+    if lower:
+        if mu in (1, 2, 3, 5):
+            m = -m
+    return m
+
+#Minkowski tensor using the convention (+,-,-,-) used in the Quantum Field
+#Theory
+minkowski_tensor = Matrix( (
+    (1, 0, 0, 0),
+    (0, -1, 0, 0),
+    (0, 0, -1, 0),
+    (0, 0, 0, -1)
+))
+
+
+@deprecated(
+    """
+    The sympy.physics.matrices.mdft method is deprecated. Use
+    sympy.DFT(n).as_explicit() instead.
+    """,
+    deprecated_since_version="1.9",
+    active_deprecations_target="deprecated-physics-mdft",
+)
+def mdft(n):
+    r"""
+    .. deprecated:: 1.9
+
+       Use DFT from sympy.matrices.expressions.fourier instead.
+
+       To get identical behavior to ``mdft(n)``, use ``DFT(n).as_explicit()``.
+    """
+    from sympy.matrices.expressions.fourier import DFT
+    return DFT(n).as_mutable()