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-core/src/models/dast.rs

@@ -244,6 +244,7 @@ pub struct DastFinding {
 }
 
 impl DastFinding {
+    #[allow(clippy::too_many_arguments)]
     pub fn new(
         scan_run_id: String,
         target_id: String,