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/domains/thought.rs

@@ -25,6 +25,8 @@ pub struct Model {
     pub reply_to_id: Option<Uuid>,
     pub visibility: Visibility,
     pub created_at: DateTimeWithTimeZone,
+    #[sea_orm(column_type = "custom(\"tsvector\")", nullable, ignore)]
+    pub search_document: Option<String>,
 }
 
 #[derive(Copy, Clone, Debug, EnumIter, DeriveRelation)]

thoughts-backend/models/src/domains/user.rs

@@ -19,6 +19,8 @@ pub struct Model {
     pub custom_css: Option<String>,
     pub created_at: DateTimeWithTimeZone,
     pub updated_at: DateTimeWithTimeZone,
+    #[sea_orm(column_type = "custom(\"tsvector\")", nullable, ignore)]
+    pub search_document: Option<String>,
 }
 
 #[derive(Copy, Clone, Debug, EnumIter, DeriveRelation)]