feat(domain): SearchPort trait with thought and user search

crates/domain/src/ports.rs

@@ -136,3 +136,21 @@ pub trait FeedRepository: Send + Sync {
     async fn public_feed(&self, page: &PageParams, viewer_id: Option<&UserId>) -> Result<Paginated<FeedEntry>, DomainError>;
     async fn search(&self, query: &str, page: &PageParams, viewer_id: Option<&UserId>) -> Result<Paginated<FeedEntry>, DomainError>;
 }
+
+#[async_trait]
+pub trait SearchPort: Send + Sync {
+    /// Full-text search over public thoughts, ranked by trigram similarity.
+    async fn search_thoughts(
+        &self,
+        query: &str,
+        page: &PageParams,
+        viewer_id: Option<&UserId>,
+    ) -> Result<Paginated<FeedEntry>, DomainError>;
+
+    /// Search users by username or display_name, ranked by trigram similarity.
+    async fn search_users(
+        &self,
+        query: &str,
+        page: &PageParams,
+    ) -> Result<Paginated<User>, DomainError>;
+}

crates/domain/src/testing.rs

@@ -282,6 +282,15 @@ pub struct TestStore {
     }
 }
 
+#[async_trait] impl SearchPort for TestStore {
+    async fn search_thoughts(&self, _q: &str, _p: &PageParams, _v: Option<&UserId>) -> Result<Paginated<FeedEntry>, DomainError> {
+        Ok(Paginated { items: vec![], total: 0, page: 1, per_page: 20 })
+    }
+    async fn search_users(&self, _q: &str, _p: &PageParams) -> Result<Paginated<User>, DomainError> {
+        Ok(Paginated { items: vec![], total: 0, page: 1, per_page: 20 })
+    }
+}
+
 #[async_trait] impl EventPublisher for TestStore {
     async fn publish(&self, event: &DomainEvent) -> Result<(), DomainError> {
         self.events.lock().unwrap().push(event.clone());
@@ -293,3 +302,23 @@ pub struct NoOpEventPublisher;
 #[async_trait] impl EventPublisher for NoOpEventPublisher {
     async fn publish(&self, _e: &DomainEvent) -> Result<(), DomainError> { Ok(()) }
 }
+
+#[cfg(test)]
+mod search_tests {
+    use super::*;
+    use crate::models::feed::PageParams;
+
+    #[tokio::test]
+    async fn test_store_search_thoughts_returns_empty() {
+        let store = TestStore::default();
+        let result = store.search_thoughts("hello", &PageParams { page: 1, per_page: 20 }, None).await.unwrap();
+        assert_eq!(result.total, 0);
+    }
+
+    #[tokio::test]
+    async fn test_store_search_users_returns_empty() {
+        let store = TestStore::default();
+        let result = store.search_users("alice", &PageParams { page: 1, per_page: 20 }).await.unwrap();
+        assert_eq!(result.total, 0);
+    }
+}