已知\(⊙\)\(C\)经过圆\(x\)\({\,\!}^{2}+\)\(y\)\({\,\!}^{2}+2\)\(x\)\(+\)\(m\)\(=0\) \((\)\(m\)\( < 1\),且\(m\)\(\neq 0)\)与\(x\)轴的交点,和点\((0,\)\(m\)\().\)
\((1)\)求\(⊙\)\(C\)的方程;
\((2)\)证明\(⊙\)\(C\)经过两个定点\(P\),\(Q\),并求出这两个定点的坐标;
\((3)\)经过其中一个定点作两条互相垂直的直线分别与\(⊙\)\(M\):\(x\)\({\,\!}^{2}+\)\(y\)\({\,\!}^{2}+2\)\(x\)\(-3=0\)相交于\(A\),\(B\)和\(C\),\(D\)点,试求\(AB\)\(·\)\(CD\)的最大值.