Fix module-graph 404 on deployed site and clippy warnings

Add export_module_graph to docs.yml CI so the JSON is generated before
mdbook build. Fix two clippy warnings in the example (complex type,
no-op replace).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: GiggleLiu

.github/workflows/docs.yml

@@ -39,6 +39,7 @@ jobs:
           cargo run --example export_petersen_mapping
           cargo run --example export_graph
           cargo run --example export_schemas
+          cargo run --example export_module_graph
 
       - name: Build mdBook
         run: mdbook build

examples/export_module_graph.rs

@@ -103,7 +103,8 @@ fn main() {
     }
 
     // Add well-known non-model modules with their key items
-    let static_modules: &[(&str, &str, &[(&str, &str, &str)])] = &[
+    type ModuleSpec = (&'static str, &'static str, &'static [(&'static str, &'static str, &'static str)]);
+    let static_modules: &[ModuleSpec] = &[
         (
             "traits",
             "core",
@@ -298,7 +299,7 @@ fn main() {
             ModuleNode {
                 name: name.clone(),
                 category: category.clone(),
-                doc_path: format!("{}/index.html", name.replace('/', "/")),
+                doc_path: format!("{name}/index.html"),
                 items,
             }
         })