Web Worker: WASM-inferenssi erillisessä säikeessä, UI ei jäädy

- Poistettu kaikki web_sys::window() -kutsut Rust WASM:sta
- Uudet Worker-yhteensopivat apufunktiot: perf_now(), worker_fetch(), sleep_ms()
- worker.js lataa ja ajaa WASM-moduulin erillisessä säikeessä
- ensureCoderNode käynnistää Workerin pääsäikeen sijaan
- Selaimen UI pysyy responsiivisena inferenssin aikana

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

network-poc/node/src/qwen_coder.rs

@@ -140,10 +140,7 @@ async fn ensure_cached(key: &str, url: &str, ws: &Rc<RefCell<WebSocket>>) -> Res
 
     console_log!("[Coder] Ladataan {}...", key);
 
-    let window = web_sys::window().unwrap();
-    let resp_val = wasm_bindgen_futures::JsFuture::from(window.fetch_with_str(url))
-        .await.map_err(|e| format!("Fetch: {:?}", e))?;
-    let resp: web_sys::Response = resp_val.dyn_into().map_err(|_| "Ei Response".to_string())?;
+    let resp = crate::worker_fetch(url).await?;
     if !resp.ok() { return Err(format!("HTTP {}", resp.status())); }
 
     let total_size: usize = resp.headers()
@@ -251,17 +248,16 @@ async fn get_or_build_model(use_3b: bool, ws: &Rc<RefCell<WebSocket>>) -> Result
 
 /// use_3b: false = 0.5B (nopea), true = 3B (laadukas)
 pub async fn run_coder_inference(prompt: String, ws: Rc<RefCell<WebSocket>>, use_3b: bool, task_id: Option<String>) {
-    let perf = web_sys::window().unwrap().performance().unwrap();
     let size_label = if use_3b { "3B" } else { "0.5B" };
 
-    let start_load = perf.now();
+    let start_load = crate::perf_now();
 
     if let Err(e) = get_or_build_model(use_3b, &ws).await {
         console_log!("[Coder] Mallin lataus: {}", e);
         return;
     }
 
-    let load_time = perf.now() - start_load;
+    let load_time = crate::perf_now() - start_load;
     if load_time > 100.0 {
         console_log!("[Coder] Malli ladattu ({:.0}ms). Generoidaan...", load_time);
     }
@@ -297,7 +293,7 @@ pub async fn run_coder_inference(prompt: String, ws: Rc<RefCell<WebSocket>>, use
         console_log!("[Coder] Syöte: {} tokenia", input_len);
 
         let device = Device::Cpu;
-        let start_gen = perf.now();
+        let start_gen = crate::perf_now();
         let eos_token = 151645u32;
         let temperature: f32 = 0.7;
         let top_k: usize = 40;
@@ -373,7 +369,7 @@ pub async fn run_coder_inference(prompt: String, ws: Rc<RefCell<WebSocket>>, use
             tokens_generated += 1;
         }
 
-        let gen_time = perf.now() - start_gen;
+        let gen_time = crate::perf_now() - start_gen;
 
         // Siivotaan vastaus: poista markdown-koodiblokit ja johdantotekstit
         let cleaned = strip_markdown_wrapper(&generated_text);