Nomad changes

docs/snippets/rust/plugins/stateful_plugin.md

@@ -0,0 +1,47 @@
+```rust title="Rust"
+use std::sync::{Arc, Mutex};
+use std::sync::atomic::{AtomicUsize, Ordering};
+use kreuzberg::KreuzbergError;
+
+struct StatefulPlugin {
+    call_count: AtomicUsize,
+    cache: Mutex<HashMap<String, String>>,
+}
+
+impl Plugin for StatefulPlugin {
+    fn name(&self) -> &str { "stateful-plugin" }
+    fn version(&self) -> String { "1.0.0".to_string() }
+
+    fn initialize(&self) -> Result<()> {
+        self.call_count.store(0, Ordering::Release);
+        Ok(())
+    }
+
+    fn shutdown(&self) -> Result<()> {
+        let count = self.call_count.load(Ordering::Acquire);
+        println!("Plugin called {} times", count);
+        Ok(())
+    }
+}
+
+#[async_trait]
+impl PostProcessor for StatefulPlugin {
+    async fn process(
+        &self,
+        result: &mut ExtractionResult,
+        _config: &ExtractionConfig
+    ) -> Result<()> {
+        self.call_count.fetch_add(1, Ordering::AcqRel);
+
+        let mut cache = self.cache.lock()
+            .map_err(|_| KreuzbergError::plugin("Cache lock poisoned"))?;
+        cache.insert("last_mime".to_string(), result.mime_type.clone());
+
+        Ok(())
+    }
+
+    fn processing_stage(&self) -> ProcessingStage {
+        ProcessingStage::Middle
+    }
+}
+```