fix(cli): wire sessions_dir() through SessionStore::from_cwd() (#41)

The CLI was using a flat cwd/.claw/sessions/ path without workspace
fingerprinting, while SessionStore::from_cwd() adds a hash subdirectory.
This mismatch meant the isolation machinery existed but wasn't actually
used by the main session management codepath.

Now sessions_dir() delegates to SessionStore::from_cwd(), ensuring all
session operations use workspace-fingerprinted directories.

Author: code-yeongyu

rust/crates/rusty-claude-cli/src/main.rs

@@ -4305,9 +4305,9 @@ impl LiveCli {
 
 fn sessions_dir() -> Result<PathBuf, Box<dyn std::error::Error>> {
     let cwd = env::current_dir()?;
-    let path = cwd.join(".claw").join("sessions");
-    fs::create_dir_all(&path)?;
-    Ok(path)
+    let store = runtime::SessionStore::from_cwd(&cwd)
+        .map_err(|e| Box::new(e) as Box<dyn std::error::Error>)?;
+    Ok(store.sessions_dir().to_path_buf())
 }
 
 fn create_managed_session_handle(