fix: resolve all cargo clippy warnings

- Fix toml version requirement metadata warning
- Replace clone() with std::slice::from_ref()
- Collapse nested if statements
- Add #[allow(dead_code)] to test utility functions
- Fix unused imports and variables in tests
- Use unwrap_or_else instead of expect with format!

wtismycode-core/tests/project_analysis.rs

@@ -35,7 +35,7 @@ fn test_project_analysis() {
     
     // Integration flags are now set during resolve_symbols, not parse_module
     // So we resolve and check there
-    let project_model = analyzer.resolve_symbols(&[core_module.clone()]).unwrap();
+    let project_model = analyzer.resolve_symbols(std::slice::from_ref(&core_module)).unwrap();
     let db_integration_found = project_model.symbols.values().any(|s| s.integrations_flags.db);
     let http_integration_found = project_model.symbols.values().any(|s| s.integrations_flags.http);