Add map analysis tool for nav2

[chant29]

Summary

Added a map analysis tool that allows the LLM to directly read and utilize Nav2 map data, and implemented read/write tools for semantic maps.

Added tools

Tool	Purpose
get_verified_maps_list	Returns the list of all available verified map specifications so the LLM can check which maps have predefined context before loading them.
get_verified_maps_info	Retrieves the detailed specification and usage context for a pre-verified map after confirming it exists in the verified list.
write_map_location	Adds or updates a semantic location entry (name, description, x, y, yaw) in the selected map’s YAML specification file.
draw_map_axes	Adds world-aligned +X/+Y axes and grid lines to the saved OccupancyGrid map image (received_map.png), drawing the axes from the world-frame origin using the height, width, and resolution supplied by the Nav2 map server, resulting in an annotated map suitable for LLM-based spatial reasoning.
analyze_previously_received_map	Loads the latest processed map overlay (received_map_overlay.png) with axes and grid already drawn, and returns it in ImageContent for LLM-based visual analysis.

Required Modifications for This Tool

Tool	Modifications
subscribe_once&subscribe_duration	Added msg_type as an additional parameter to parse_input.

function	Modifications
parse_input	If the input msg_type ends with OccupancyGrid, call the parse_map function.
parse_map	The OccupancyGrid values (0 = free, −1 = unknown, 100 = occupied) are mapped to grayscale intensities (127, 255, and 0) and export the result as an image(received_map.png).

How to Use

When Nav2 is running, providing the LLM with scripts such as ‘retrieve the map image and draw the axes’ or ‘fetch the map image’ causes it to invoke the given tools. Through these tools, the LLM can analyze the map image data and understand the map’s structure and coordinate system.

Example 1 : Analyze the map image to determine what kind of space this is.

Example 2 : Interpret the user’s requested destination, calculate its coordinates, and navigate to that point.