Add DAST, graph modules, toast notifications, and dashboard enhancements

Add DAST scanning and code knowledge graph features across the stack:
- compliance-dast and compliance-graph workspace crates
- Agent API handlers and routes for DAST targets/scans and graph builds
- Core models and traits for DAST and graph domains
- Dashboard pages for DAST targets/findings/overview and graph explorer/impact
- Toast notification system with auto-dismiss for async action feedback
- Button click animations and disabled states for better UX

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

Cargo.toml

@@ -1,5 +1,11 @@
 [workspace]
-members = ["compliance-core", "compliance-agent", "compliance-dashboard"]
+members = [
+    "compliance-core",
+    "compliance-agent",
+    "compliance-dashboard",
+    "compliance-graph",
+    "compliance-dast",
+]
 resolver = "2"
 
 [workspace.lints.clippy]