Tab completion conflict between main.py and manager_requirements.txt

Historically, running the project involved:

```bash
python m
```
The introduction of `manager_requirements.txt` creates a tab-completion ambiguity that now requires manual disambiguation.

While minor per invocation, this adds an estimated ~200–300ms of latency (excluding context switching and emotional overhead).

This cost compounds significantly when:

- running the project frequently
- working across multiple clones or environments

Over time, this represents a non-trivial regression in developer ergonomics by turning a zero-thought muscle-memory action into a conscious one.

Mentioning this here in case others have run into the same friction.