build(deps): Bump libtmux to ==0.51.0

why: Update to latest libtmux with improved API and DeprecatedError for legacy APIs
what:
- Update pyproject.toml dependency constraint from >=0.37.0 to ==0.51.0

Author: tony

pyproject.toml

@@ -12,7 +12,7 @@ dependencies = [
     "sqlalchemy>=2.0.0",
     "uvicorn[standard]>=0.24.0",
     "websockets>=12.0",
-    "libtmux>=0.37.0",
+    "libtmux==0.51.0",
     "aiofiles>=24.1.0",
     "click>=8.0.0",
     "python-frontmatter>=1.1.0",