test: update tests and benchmarks for ensemble architecture

- Rewrite DDoS tests to use ensemble detector (remove KNN model setup)
- Update scanner tests for ensemble-based detection
- Remove legacy model construction helpers from benchmarks
- Add copyright headers to test files

Signed-off-by: Sienna Meridian Satterwhite <sienna@sunbeam.pt>

tests/e2e.rs

@@ -1,3 +1,6 @@
+// Copyright Sunbeam Studios 2026
+// SPDX-License-Identifier: Apache-2.0
+
 //! End-to-end tests: spin up a real SunbeamProxy over plain HTTP, route it
 //! to a tiny TCP echo-backend, and verify that the upstream receives the
 //! correct X-Forwarded-Proto header.
@@ -108,7 +111,7 @@ fn start_proxy_once(backend_port: u16) {
         }];
         let acme_routes: AcmeRoutes = Arc::new(RwLock::new(HashMap::new()));
         let compiled_rewrites = SunbeamProxy::compile_rewrites(&routes);
-        let proxy = SunbeamProxy { routes, acme_routes, ddos_detector: None, scanner_detector: None, bot_allowlist: None, rate_limiter: None, compiled_rewrites, http_client: reqwest::Client::new(), pipeline_bypass_cidrs: vec![], cluster: None };
+        let proxy = SunbeamProxy { routes, acme_routes, ddos_detector: None, scanner_detector: None, bot_allowlist: None, rate_limiter: None, compiled_rewrites, http_client: reqwest::Client::new(), pipeline_bypass_cidrs: vec![], cluster: None, ddos_observe_only: false, scanner_observe_only: false };
 
         let opt = Opt {
             upgrade: false,