refactor(convex): separar heartbeat em tabela dedicada para evitar OOM

- Criar tabela machineHeartbeats para armazenar lastHeartbeatAt separadamente
- Modificar heartbeat para so atualizar machines quando ha mudancas reais
- Atualizar queries listByTenant e getById para usar nova tabela
- Reducao drastica de versoes de documentos criadas a cada heartbeat

Antes: ~54 versoes por maquina (3524 linhas para 65 maquinas)
Agora: heartbeat atualiza documento leve, machines so muda com dados novos

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

convex/_generated/server.js

@@ -16,7 +16,6 @@ import {
   internalActionGeneric,
   internalMutationGeneric,
   internalQueryGeneric,
-  componentsGeneric,
 } from "convex/server";
 
 /**
@@ -81,10 +80,14 @@ export const action = actionGeneric;
 export const internalAction = internalActionGeneric;
 
 /**
- * Define a Convex HTTP action.
+ * Define an HTTP action.
  *
- * @param func - The function. It receives an {@link ActionCtx} as its first argument, and a `Request` object
- * as its second.
- * @returns The wrapped endpoint function. Route a URL path to this function in `convex/http.js`.
+ * The wrapped function will be used to respond to HTTP requests received
+ * by a Convex deployment if the requests matches the path and method where
+ * this action is routed. Be sure to route your httpAction in `convex/http.js`.
+ *
+ * @param func - The function. It receives an {@link ActionCtx} as its first argument
+ * and a Fetch API `Request` object as its second.
+ * @returns The wrapped function. Import this function from `convex/http.js` and route it to hook it up.
  */
 export const httpAction = httpActionGeneric;