PlugOS refactor and other tweaks (#631)

* Prep for in-process plug loading (e.g. for CF workers, Deno Deploy)
* Prototype of fixed in-process loading plugs
* Fix: buttons not to scroll with content
* Better positioning of modal especially on mobile
* Move query caching outside query
* Fix annoying mouse behavior when filter box appears
* Page navigator search tweaks

web/syscalls/util.ts

@@ -18,8 +18,11 @@ export async function proxySyscall(
   name: string,
   args: any[],
 ): Promise<any> {
+  if (!ctx.plug) {
+    throw new Error(`Cannot proxy ${name} syscall without plug context`);
+  }
   const resp = await httpSpacePrimitives.authenticatedFetch(
-    `${httpSpacePrimitives.url}/.rpc/${ctx.plug.name}/${name}`,
+    `${httpSpacePrimitives.url}/.rpc/${ctx.plug}/${name}`,
     {
       method: "POST",
       body: JSON.stringify(args),