The graph holds what a module declares, not only what it was built on

Build edges are discovered by building; requires and provides are stated by the
module about itself. Both belong in the graph and answer different questions —
and "what provides postgres-database" needed a sweep over every manifest, which
only something holding all of them can do.

modules/mesh-catalog/tools/index.ts

@@ -31,6 +31,17 @@ export function getCatalogueTools(graph: Graph): ToolDefinition[] {
         return found ? { module: found } : { error: `the catalogue holds no ${module}` };
       },
     },
+    {
+      name: "catalog_provides",
+      description:
+        "What provides a provision, and what needs it. Answered from what modules declare about themselves, so it does not require holding every manifest at once.",
+      input: { provision: { type: "string", description: "the provision, e.g. postgres-database" } },
+      run: async (args) => {
+        const provision = String(args.provision ?? "");
+        if (!provision) return { error: "name a provision" };
+        return await graph.whoProvides(provision);
+      },
+    },
     {
       name: "catalog_dependents",
       description: