fix(lock): use recursive mkdir for lock path creation

Ensures parent directories exist when creating lock directory.

Author: jdalton

src/process-lock.ts

@@ -257,7 +257,7 @@ class ProcessLockManager {
           }
 
           // Atomic lock acquisition via mkdir.
-          mkdirSync(lockPath, { recursive: false })
+          mkdirSync(lockPath, { recursive: true })
 
           // Track lock for cleanup.
           this.activeLocks.add(lockPath)