Add environment variable support for root directory configuration

Enable setting the root directory via DEMON_ROOT_DIR environment variable by adding 'env' feature to clap and configuring the root_dir argument to read from environment.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

1 files changed, 1 insertions, 1 deletions

diff --git a/src/main.rs b/src/main.rs
index 05208ea..6fbab07 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -120,7 +120,7 @@ struct Cli {
 #[derive(Args)]
 struct Global {
     /// Root directory for daemon files (pid, logs). If not specified, searches for git root.
-    #[arg(long, global = true)]
+    #[arg(long, global = true, env = "DEMON_ROOT_DIR")]
     root_dir: Option<PathBuf>,
 }