feat(api): on-write search reindex after catalogue writes (#17)

Wire best-effort Meilisearch index sync into the admin write paths
(create/update/delete/set_fields/set_visibility). Adds
SearchClient::sync_object (reindex if the object exists, remove if gone —
one uniform path), an optional AppState.search client, and a reindex
helper that logs failures via tracing without failing the committed
write. Server gains MEILI_URL/MEILI_MASTER_KEY/MEILI_INDEX config;
search stays disabled (no-op) when unset. reindex_all remains the
recovery path.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

crates/search/src/lib.rs

@@ -40,6 +40,7 @@ pub struct SearchDocument {
 }
 
 /// A Meilisearch-backed search client scoped to one index.
+#[derive(Clone)]
 pub struct SearchClient {
     client: meilisearch_sdk::client::Client,
     index_uid: String,
@@ -146,6 +147,23 @@ impl SearchClient {
             .collect()
     }
 
+    /// Sync a single object's index entry with the database after a catalogue write
+    /// commits: re-project and index it if it still exists, otherwise remove it. This
+    /// is the uniform on-write path for create/update/delete/field/visibility changes —
+    /// a delete (object gone) removes the entry; everything else re-indexes the current
+    /// projection. Best-effort: callers invoke it after the DB transaction commits and
+    /// log (not propagate) any error, since `reindex_all` is the recovery path.
+    pub async fn sync_object(&self, db: &Db, id: ObjectId) -> Result<(), SearchError> {
+        match db::catalog::object_by_id(db.pool(), id).await? {
+            Some(object) => {
+                let document = build_document(db, &object).await?;
+
+                self.index_object(&document).await
+            }
+            None => self.remove_object(id).await,
+        }
+    }
+
     /// Rebuild the whole index from the database (clears then re-adds all objects).
     pub async fn reindex_all(&self, db: &Db) -> Result<(), SearchError> {
         let index = self.client.index(&self.index_uid);