fix: invoke claude-code-hooks PreCompact in session compacting handler

The experimental.session.compacting handler was not delegating to
claudeCodeHooks, making PreCompact hooks from .claude/settings.json
dead code. Also fixed premature early-return when compactionContextInjector
was null which would skip any subsequent hooks.

src/index.ts

@@ -80,10 +80,13 @@ const OhMyOpenCodePlugin: Plugin = async (ctx) => {
       output: { context: string[] },
     ): Promise<void> => {
       await hooks.compactionTodoPreserver?.capture(_input.sessionID)
-      if (!hooks.compactionContextInjector) {
-        return
+      await hooks.claudeCodeHooks?.["experimental.session.compacting"]?.(
+        _input,
+        output,
+      )
+      if (hooks.compactionContextInjector) {
+        output.context.push(hooks.compactionContextInjector(_input.sessionID))
       }
-      output.context.push(hooks.compactionContextInjector(_input.sessionID))
     },
   }
 }