feat: add schema listing functionality

- Add find method to CordraClient for querying objects
- Implement cordra://schemas resource for listing available type schemas
- Add comprehensive unit tests for both client find method and server schema listing
- Handle CordraPy response format with results array extraction
- Support schema name extraction from returned objects

src/mcp_cordra/client.py

@@ -78,3 +78,32 @@ class CordraClient:
                 raise CordraNotFoundError(f"Object not found: {object_id}") from e
             raise CordraClientError(f"Failed to retrieve object {object_id}: {e}") from e
 
+    async def find(self, query: str) -> list[dict[str, Any]]:
+        """Find objects using a Cordra query.
+        
+        Args:
+            query: The query string to search for objects
+            
+        Returns:
+            List of objects matching the query as dictionaries
+            
+        Raises:
+            CordraClientError: If there's an API error
+        """
+        try:
+            # Use CordraPy to find objects
+            # TODO - need to handle pagination, but the CordraPy API does not support it.
+            response: dict[str, Any] = cordra.CordraObject.find(
+                self.config.cordra_url,  # type: ignore
+                query
+            )
+            
+            # Extract the results array from the response
+            if isinstance(response, dict) and 'results' in response:
+                return response['results']
+            else:
+                return []
+        
+        except Exception as e:
+            raise CordraClientError(f"Failed to search with query '{query}': {e}") from e
+

src/mcp_cordra/server.py

@@ -42,6 +42,36 @@ async def get_cordra_object(prefix: str, suffix: str) -> str:
         raise RuntimeError(f"Failed to retrieve object {object_id}: {e}") from e
 
 
+@mcp.resource("cordra://schemas", name="cordra-schemas-list", description="List available Cordra type schemas")
+async def list_cordra_schemas() -> str:
+    """List available Cordra type schemas.
+    
+    Returns:
+        JSON array of available schema names
+        
+    Raises:
+        RuntimeError: If there's an API error
+    """
+    try:
+        # Use the client's find method to get all schema objects
+        schemas = await cordra_client.find("type:Schema")
+        
+        # Extract the names from the schema objects
+        schema_names = []
+        for schema in schemas:
+            if isinstance(schema, dict) and 'name' in schema:
+                schema_names.append(schema['name'])
+        
+        result = {
+            "schemas": schema_names,
+            "count": len(schema_names)
+        }
+        return json.dumps(result, indent=2)
+        
+    except Exception as e:
+        raise RuntimeError(f"Failed to list schemas: {e}") from e
+
+
 @mcp.tool()
 async def ping() -> str:
     """Simple ping tool to test server connectivity."""