$$I_{k,m}(n)=\int_{0}^{1}u^k\cot{\frac{\pi(1-u)}{m}}\sin{\frac{2\pi n(1-u)}{m}}\,du$$$$I_{k,m}(n)=\int_{0}^{1}u^k\cot\left({\frac{\pi(1-u)}{m}}\right)\sin\left({\frac{2\pi n(1-u)}{m}}\right)\,du$$
Conjecture:$$\lim_{n\rightarrow\infty} I_{k,m}(n)=\frac{1}{2}m, \;\;\text{for}\;\; m\geq 1\;\; \text{and any} \;\;k\in\{1,2,3,\ldots\}.$$
No proof $\lim_{n\rightarrow\infty} I_{k,m}(n)=m/2$(yet), but the plot below gives the numerical evidence. It is a collection of graphs of $I_{k,m}(n)$ as a function of $m$, for fixed $m\geq 1$$n=500$ and any $k\in\{1,2,3,\ldots\}$$k$ taking the values 1,2,3,4,5.