fix: MCP instructions name body_topology, not a list_edges tool (#729)

The MCP server instructions now point to `body_topology` for finding edge points (there is no `list_edges` tool), with a test that every tool the instructions name exists.

crates/mcp/src/server.rs

@@ -29,7 +29,7 @@ and degrees in expressions (internally radians), Z is up. Model like in Fusion:
 and dimension (`sketch.dimension {entities, value}`; values may name parameters), `sketch.finish`, then features \
 (`solid.extrude {distance, operation?: new|join|cut|intersect}`, `solid.revolve`, `solid.fillet {edges: [[x,y,z] point on \
 edge], radius}`, `solid.chamfer`, patterns, mirror, primitives). Use `batch` for several steps at once, \
-`list_commands` for ids and parameter docs, `inspect_design` / `measure` to verify, `list_edges` to find edge points, \
+`list_commands` for ids and parameter docs, `inspect_design` / `measure` to verify, `body_topology` to find edge points, \
 `set_parameter` to drive the design and `screenshot` to look at it.";
 
 pub struct Server {