Add graph explorer components, API handlers, and dependency updates

Adds code inspector, file tree components, graph visualization JS,
graph API handlers, sidebar navigation updates, and misc improvements.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

compliance-dashboard/src/components/mod.rs

@@ -1,5 +1,7 @@
 pub mod app_shell;
+pub mod code_inspector;
 pub mod code_snippet;
+pub mod file_tree;
 pub mod page_header;
 pub mod pagination;
 pub mod severity_badge;