docs: document JSONB literals work without explicit type casts

Add notes to searchable-json.md clarifying that JSONB literals in INSERT,
UPDATE, and containment operations work directly without ::jsonb type
annotations. The proxy infers the JSONB type from the target column.

Also adds docstring to map_jsonb integration test explaining the
intentional absence of type casts.

Author: tobyhede

docs/reference/searchable-json.md

@@ -43,6 +43,8 @@ SELECT eql_v2.add_search_config(
 );
 ```
 
+> **Note:** JSONB literals in INSERT and UPDATE statements work directly without explicit `::jsonb` type casts. The proxy infers the JSONB type from the target column and handles encryption transparently.
+
 ### JSON document structure
 
 Examples assume an encrypted JSON document with the following structure:
@@ -591,6 +593,8 @@ SELECT jsonb_array_length(jsonb_path_query(encrypted_jsonb, '$.unknown')) FROM c
 
 ## Containment Operators
 
+> **Note:** Containment operators work directly with JSONB literals without requiring explicit `::jsonb` type casts. The examples below use the simplified syntax intentionally.
+
 ### `@>` (Contains Operator)
 
 Tests whether the left JSONB value contains the right JSONB value.

packages/cipherstash-proxy-integration/src/map_literals.rs

@@ -45,6 +45,11 @@ mod tests {
         println!("encrypted: {:?}", rows[0])
     }
 
+    /// Verify JSONB literal insertion and retrieval without explicit type casts.
+    ///
+    /// JSONB literals in INSERT and SELECT statements work directly with the proxy
+    /// without requiring `::jsonb` type annotations. The proxy infers the JSONB type
+    /// from the target column and handles encryption/decryption transparently.
     #[tokio::test]
     async fn map_jsonb() {
         trace();