Limit the app container to 1 CPU and 2 GB, and stop stale caches

The app container is now created with --cpus 1 --memory 2048m: the heavy
work happens in the computers' own containers, so the orchestrator does
not need more. Both are installer flags (--cpus, --memory), kept in
install.conf, and part of the idempotency check, so an existing install
picks them up on its next update.

The env and app-setting caches lived in module variables, and bunext
bundles pages and API routes separately. A save cleared only its own
copy, so a saved provider key never reached the page that lists models
until the process restarted. They now share one slot per name on
globalThis, behind a symbol from the global registry, with the pattern
extracted into a tested helper.

src/utils/global-cache.test.ts

@@ -0,0 +1,54 @@
+import { describe, expect, test } from "bun:test";
+import globalCache from "./global-cache";
+
+describe("globalCache", () => {
+    test("keeps a value and clears it", () => {
+        const cache = globalCache<number>({ name: "cobble.grabAllEnvs.cache" });
+
+        cache.clear();
+        expect(cache.get()).toBeUndefined();
+
+        cache.set(7);
+        expect(cache.get()).toBe(7);
+
+        cache.clear();
+        expect(cache.get()).toBeUndefined();
+    });
+
+    test("two slots with one name share a value, as two bundles would", () => {
+        const page_bundle = globalCache<string>({
+            name: "cobble.grabAppSettings.cache",
+        });
+        const api_bundle = globalCache<string>({
+            name: "cobble.grabAppSettings.cache",
+        });
+
+        page_bundle.clear();
+        page_bundle.set("stale");
+
+        // The API sees what the page wrote, so a save there clears it too.
+        expect(api_bundle.get()).toBe("stale");
+
+        api_bundle.clear();
+        expect(page_bundle.get()).toBeUndefined();
+    });
+
+    test("different names never share a slot", () => {
+        const envs = globalCache<string>({ name: "cobble.grabAllEnvs.cache" });
+        const settings = globalCache<string>({
+            name: "cobble.grabAppSettings.cache",
+        });
+
+        envs.clear();
+        settings.clear();
+
+        envs.set("a");
+        settings.set("b");
+
+        expect(envs.get()).toBe("a");
+        expect(settings.get()).toBe("b");
+
+        envs.clear();
+        settings.clear();
+    });
+});