feat(xy): daemon Registry with config-hash entries

crates/xy/src/daemon/mod.rs

@@ -1,4 +1,6 @@
 use crate::paths::Paths;
 use anyhow::{bail, Result};
 
+pub mod registry;
+
 pub async fn run(_paths: Paths) -> Result<()> { bail!("not implemented") }

crates/xy/src/daemon/registry.rs

@@ -0,0 +1,39 @@
+use std::collections::HashMap;
+use std::sync::Arc;
+use tokio::sync::RwLock;
+use xy_supervisor::SupervisorHandle;
+
+#[derive(Clone)]
+pub struct Entry {
+    pub handle: SupervisorHandle,
+    pub config_hash: u64,
+}
+
+#[derive(Clone, Default)]
+pub struct Registry {
+    inner: Arc<RwLock<HashMap<String, Entry>>>,
+}
+
+impl Registry {
+    pub fn new() -> Self { Self::default() }
+    pub async fn insert(&self, name: String, entry: Entry) {
+        self.inner.write().await.insert(name, entry);
+    }
+    pub async fn remove(&self, name: &str) -> Option<Entry> {
+        self.inner.write().await.remove(name)
+    }
+    pub async fn get(&self, name: &str) -> Option<Entry> {
+        self.inner.read().await.get(name).cloned()
+    }
+    pub async fn names(&self) -> Vec<String> {
+        let g = self.inner.read().await;
+        let mut v: Vec<String> = g.keys().cloned().collect();
+        v.sort(); v
+    }
+    pub async fn snapshot(&self) -> Vec<(String, Entry)> {
+        let g = self.inner.read().await;
+        let mut v: Vec<_> = g.iter().map(|(k, v)| (k.clone(), v.clone())).collect();
+        v.sort_by(|a, b| a.0.cmp(&b.0));
+        v
+    }
+}