refactor: share env-bool parsing and logging setup

env_utils.env_bool replaces duplicated truthy parsing in config and
rembg_cli. logging_config.configure_logging unifies entry-point setup.

Co-authored-by: Cursor <cursoragent@cursor.com>

app/rembg_cli.py

@@ -18,12 +18,7 @@ import sys
 import traceback
 from pathlib import Path
 
-
-def _env_bool(name: str, default: bool) -> bool:
-    raw = os.environ.get(name)
-    if raw is None:
-        return default
-    return raw.strip().lower() in {"1", "true", "yes", "on"}
+from .env_utils import env_bool
 
 
 def main() -> int:
@@ -42,7 +37,7 @@ def main() -> int:
         output_path.parent.mkdir(parents=True, exist_ok=True)
 
         model = os.environ.get("REMBG_MODEL", "u2net")
-        alpha = _env_bool("REMBG_ALPHA", True)
+        alpha = env_bool("REMBG_ALPHA", True)
         session = new_session(model)
         output_path.write_bytes(
             remove(