Fix: Remove duplicate shebang from stderr-test-hook source

plugin/scripts/stderr-test-hook.js

@@ -1,3 +1,2 @@
 #!/usr/bin/env node
-#!/usr/bin/env node
 console.error("\u{1F9EA} TEST: This is a stderr message from the claude-mem hook");process.exit(0);

src/hooks/stderr-test-hook.ts

@@ -1,5 +1,3 @@
-#!/usr/bin/env node
-
 /**
  * Test hook to verify if stderr messages appear in Claude Code UI
  * This hook simply outputs a message via console.error()