Enable S101: replace assert with explicit checks in non-test code

- Replaced assert with RuntimeError in lichess_bot/main.py
- Added per-file-ignore for test_*.py pattern

PYTHON/lichess_bot/main.py

@@ -295,7 +295,9 @@ def run_bot(log_level: str = "INFO", decline_correspondence: bool = False) -> No
                             lines: list[str] = []
                             ply_line_re = __import__("re").compile(r"^\s*(\d+)\s")
                             # Read stdout line by line
-                            assert proc.stdout is not None
+                            if proc.stdout is None:
+                                msg = "subprocess stdout is None"
+                                raise RuntimeError(msg)
                             for line in proc.stdout:
                                 lines.append(line)
                                 m = ply_line_re.match(line)
@@ -321,7 +323,9 @@ def run_bot(log_level: str = "INFO", decline_correspondence: bool = False) -> No
                                         )
 
                             # Capture any remaining stderr and ensure process ends
-                            assert proc.stderr is not None
+                            if proc.stderr is None:
+                                msg = "subprocess stderr is None"
+                                raise RuntimeError(msg)
                             stderr_text = proc.stderr.read() or ""
                             ret = proc.wait()
                             analysis_text = "".join(lines)

pyproject.toml

@@ -34,7 +34,6 @@ ignore = [
     "COM812",  # Trailing comma missing (conflicts with formatter)
     "ISC001",  # Implicit string concatenation (conflicts with formatter)
     # Relaxed for script-heavy repository
-    "S101",    # Use of assert - acceptable in this codebase
     "ANN001",  # Missing type annotation for function argument
     "ANN002",  # Missing type annotation for *args
     "ANN003",  # Missing type annotation for **kwargs
@@ -102,6 +101,9 @@ unfixable = []
     "S101",    # Allow assert in tests
     "PLR2004", # Allow magic values in tests
 ]
+"**/test_*.py" = [
+    "S101",    # Allow assert in tests
+]
 "**/conftest.py" = [
     "D100",    # Allow missing module docstring
     "D103",    # Allow missing function docstring