fix: avoid top-level await in bun-runner so hooks load on Node < 14.8

bun-runner.js is an ES module that uses a top-level `await collectStdin()`.
Top-level await is unsupported by the ESM loader of Node < 14.8, so on hosts
where Claude Code invokes hooks with an older Node (e.g. the Node 12 shipped
by Ubuntu 22.04 / many WSL setups) the module fails to load with
"SyntaxError: Unexpected reserved word", breaking every claude-mem hook.

Wrap the post-collectStdin body in an async IIFE so `await` is no longer at
module scope. Same oldest-Node compatibility concern already handled in this
file for optional chaining (see the `?.` note above isPluginDisabledInClaudeSettings).

Repro: `node --check plugin/scripts/bun-runner.js` under Node 12 fails before
this change and passes after.

Author: Kurama2d

plugin/scripts/bun-runner.js

@@ -125,6 +125,12 @@ function collectStdin() {
   });
 }
 
+// Wrapped in an async IIFE: top-level `await` is unsupported in the ESM loader
+// of Node < 14.8, which some Claude Code installs invoke hooks with (e.g. the
+// Node 12 shipped by Ubuntu 22.04 / many WSL setups). There it throws
+// "SyntaxError: Unexpected reserved word" at module load, breaking the hook.
+// Same oldest-Node compatibility reason as the optional-chaining note above.
+(async () => {
 const stdinData = await collectStdin();
 
 const spawnOptions = {
@@ -236,3 +242,4 @@ child.on('close', (code, signal) => {
   }
   process.exit(code || 0);
 });
+})();