Cleanup Makefile & Improve Dev Experience

#### Problem
- The repo has both a `Makefile` and a `Taskfile.yml`, with redundant commands. We should standardize on `Taskfile.yml` and remove `Makefile`.
- Scripts are split between `scripts/` and `hack/`, and they don’t work well together.
- Running the plugin locally is a pain—too many steps, not well-documented.

#### Proposed Fix
- Remove `Makefile` to avoid duplication.
- Organize scripts in a single, consistent place.
- Improve local dev setup so it’s easier to run and debug.
- Document the procedure to run a test deployment of the local code.