feat: add Copilot optimizer to reduce premium interaction consumption

Implement request classification, tool result merging, compact detection,
deterministic request IDs, and warmup downgrade for Copilot proxy.

The root cause was x-initiator being hardcoded to "user", making Copilot
count every API request (including tool callbacks and agent continuations)
as a separate premium interaction. The optimizer dynamically classifies
requests as "user" or "agent" based on message content analysis.

Closes #1813

src-tauri/src/commands/settings.rs

@@ -247,6 +247,30 @@ pub async fn set_optimizer_config(
     Ok(true)
 }
 
+/// 获取 Copilot 优化器配置
+#[tauri::command]
+pub async fn get_copilot_optimizer_config(
+    state: tauri::State<'_, crate::AppState>,
+) -> Result<crate::proxy::types::CopilotOptimizerConfig, String> {
+    state
+        .db
+        .get_copilot_optimizer_config()
+        .map_err(|e| e.to_string())
+}
+
+/// 设置 Copilot 优化器配置
+#[tauri::command]
+pub async fn set_copilot_optimizer_config(
+    state: tauri::State<'_, crate::AppState>,
+    config: crate::proxy::types::CopilotOptimizerConfig,
+) -> Result<bool, String> {
+    state
+        .db
+        .set_copilot_optimizer_config(&config)
+        .map_err(|e| e.to_string())?;
+    Ok(true)
+}
+
 /// 获取日志配置
 #[tauri::command]
 pub async fn get_log_config(