feat: add optional llm-task JSON-only tool (#1498)

* feat(llm-task): add optional JSON-only LLM task tool

* fix(llm-task): fix invalid package.json

* fix(llm-task): fix invalid plugin manifest JSON

* fix(llm-task): fix index.ts import quoting

* fix(llm-task): load embedded runner from src or bundled dist

extensions/llm-task/package.json

@@ -0,0 +1,7 @@
+{
+  "name": "@clawdbot/llm-task",
+  "private": true,
+  "type": "module",
+  "main": "index.ts",
+  "version": "0.0.0"
+}