feat: implement full-text search functionality with API integration, add search router and persistence logic, and create related schemas and tests

thoughts-backend/models/src/schemas/mod.rs

@@ -1,3 +1,4 @@
 pub mod api_key;
+pub mod search;
 pub mod thought;
 pub mod user;

thoughts-backend/models/src/schemas/search.rs

@@ -0,0 +1,9 @@
+use super::{thought::ThoughtListSchema, user::UserListSchema};
+use serde::Serialize;
+use utoipa::ToSchema;
+
+#[derive(Serialize, ToSchema)]
+pub struct SearchResultsSchema {
+    pub users: UserListSchema,
+    pub thoughts: ThoughtListSchema,
+}