Fix clippy warnings and fmt issues to pass CI

Replace expect/unwrap calls with safe alternatives, add Default impls
for parser structs and Toasts, fix redundant closures, collapse nested
ifs, remove unused import, and allow recursive-only-self/too-many-args
lints in compliance-graph.

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

compliance-dashboard/src/components/toast.rs

@@ -20,6 +20,12 @@ pub struct Toasts {
     next_id: Signal<usize>,
 }
 
+impl Default for Toasts {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 impl Toasts {
     pub fn new() -> Self {
         Self {