perf(ui): trim hidden session and bootstrap work

packages/ui/src/components/instance/shell/useSessionCache.ts

@@ -2,10 +2,30 @@ import { createEffect, createSignal, type Accessor } from "solid-js"
 import { messageStoreBus } from "../../../stores/message-v2/bus"
 import { clearSessionRenderCache } from "../../message-block"
 import { getLogger } from "../../../lib/logger"
+import { runtimeEnv } from "../../../lib/runtime-env"
 
 const log = getLogger("session")
 
-const SESSION_CACHE_LIMIT = 5
+function getSessionCacheLimit() {
+  if (runtimeEnv.platform === "mobile") {
+    return 2
+  }
+
+  if (runtimeEnv.host === "tauri") {
+    return 3
+  }
+
+  if (typeof navigator !== "undefined") {
+    const deviceMemory = (navigator as Navigator & { deviceMemory?: number }).deviceMemory
+    if (typeof deviceMemory === "number" && deviceMemory <= 4) {
+      return 3
+    }
+  }
+
+  return 5
+}
+
+const SESSION_CACHE_LIMIT = getSessionCacheLimit()
 
 type SessionCacheOptions = {
   instanceId: Accessor<string>