Fix backend code relooping issue

Related to #11

Improve error handling and retry mechanism for backend code generation process.

* **Handle empty generated server code gracefully in `cofounder/api/system/functions/backend/server.js`**
  - Add a check to handle empty generated server code in the `backendServerGenerate` function.
  - Log a specific error message if the generated server code is empty.
  - Return an empty server code structure if the generated server code is empty.

* **Update retry mechanism in `cofounder/api/build.js`**
  - Add a condition to stop retrying if the generated server code is empty after a certain number of attempts in the `system.run` function.
  - Update the retry mechanism to include the new condition in the `fn` function.
  - Log a specific error message if the generated server code is empty after the maximum retries.

---

For more details, open the [Copilot Workspace session](https://copilot-workspace.githubnext.com/raidendotai/cofounder/issues/11?shareId=XXXX-XXXX-XXXX-XXXX).

cofounder/api/build.js

@@ -82,7 +82,7 @@ async function build({ system }) {
 						return await queues[id].add(async () => {
 							events.log.node.emit(`start`, { id, context, data });
 							const response = await retry(
-								async (bail) => {
+								async (bail, attempt) => {
 									try {
 										const fnresponse = await system.functions[id]({
 											context: { ...context, run: system.run },
@@ -94,6 +94,14 @@ async function build({ system }) {
 												: data,
 										});
 
+										if (!fnresponse || (id === 'BACKEND:SERVER::GENERATE' && !fnresponse.backend.server.main.mjs)) {
+											if (attempt >= (parseInt(system.nodes[id].queue?.retry) || 5)) {
+												console.error(`backend:server:generate error - generated is empty after ${attempt} attempts`);
+												return { success: false };
+											}
+											throw new Error("backend:server:generate error - generated is empty");
+										}
+
 										return !fnresponse
 											? { success: false }
 											: system.nodes[id].out?.length

cofounder/api/system/functions/backend/server.js

@@ -311,7 +311,20 @@ now do the analysis , write the full working script and specify the dependencies
 
 	const { mjs } = extraction;
 	if (!mjs.length || !extraction.yaml) {
-		throw new Error("backend:server:generate error - generated is empty");
+		console.error("backend:server:generate error - generated is empty");
+		return {
+			backend: {
+				...data.backend,
+				server: {
+					main: {
+						mjs: "",
+						dependencies: {},
+						env: {},
+						timestamp: Date.now(),
+					},
+				},
+			},
+		};
 	}
 
 	const parsedYaml = extraction.yaml ? yaml.parse(extraction.yaml) : {};