Fetch real model context window from server for session bar

GET /api/model-context?model=<name> 엔드포인트 추가.
Claude → 200k 고정, Ollama → /api/show 쿼리 후 model_info 또는
num_ctx 파라미터에서 실제 컨텍스트 크기 추출.
클라이언트: 모델 변경 및 초기 부팅 시 자동 fetch.

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

web-ui/code.js

@@ -3893,14 +3893,25 @@ function setCodeSbTab(tab) {
 }
 
 
-function _codeAiCtxMax() {
-  const m = (codeAiModel || '').toLowerCase();
-  if (!m || m.includes('claude')) return 200000;
-  // Common Ollama context windows
-  if (m.includes('llama3') || m.includes('llama-3') || m.includes('qwen')) return 128000;
-  if (m.includes('mistral') || m.includes('mixtral')) return 32000;
-  if (m.includes('gemma')) return 8192;
-  return 32000; // safe default for unknown local models
+let _codeAiCtxMaxCached = 200000; // default until server responds
+let _codeAiCtxMaxFetchedFor = ''; // model name the cache is valid for
+
+function _codeAiCtxMax() { return _codeAiCtxMaxCached; }
+
+async function _fetchModelCtxMax(model) {
+  const key = model || '';
+  if (key === _codeAiCtxMaxFetchedFor) return; // already fetched for this model
+  _codeAiCtxMaxFetchedFor = key;
+  try {
+    const url = '/api/model-context' + (key ? `?model=${encodeURIComponent(key)}` : '');
+    const r = await fetch(url, { headers: authHeaders() });
+    if (!r.ok) return;
+    const d = await r.json();
+    if (d.contextWindow) {
+      _codeAiCtxMaxCached = d.contextWindow;
+      updateSessionPanel();
+    }
+  } catch (_) {}
 }
 
 function updateSessionPanel() {
@@ -4143,6 +4154,8 @@ function csbModelChanged() {
   codeAiModel = sel ? sel.value : '';
   localStorage.setItem('codeAiModel', codeAiModel);
   updateCodeAiLabel();
+  _codeAiCtxMaxFetchedFor = ''; // invalidate cache so next fetch runs
+  _fetchModelCtxMax(codeAiModel);
 }
 
 function csbFontSize(val) {
@@ -4460,6 +4473,7 @@ function setupCodeVResize() {
     try { const inp = document.getElementById('csb-termpath'); if (inp && localTermPath) inp.value = localTermPath; } catch (e) {}
     try { await restoreLocalDirHandle(); } catch (e) {}
     try { updateSessionPanel(); } catch (e) {}
+    try { _fetchModelCtxMax(codeAiModel); } catch (e) {}
     try { codeSbRefresh(); } catch (e) {}
     try { companionConnect(); } catch (e) {}
     // 히스토리 없으면 세션 목록 표시