Convex MCP server

Run client-side scenarios driven by load-generator. # Usage Run [LoadGenerator](../../crates/load_generator/README.md). LoadGenerator will provision a backend and start ScenarioRunner with the given parameters. ## Adding new scenarios To add a new scenario, 1. Name the scenario and add it to `ScenarioName` and the `main` control flow in `index.ts`. 2. Write a class that implements the `IScenario` interface and extends the `Scenario` class and drop the class in the `scenarios` folder. Run this new scenario from the `main` control flow. 3. In LoadGenerator, add a new scenario to the `Scenario` struct.