🪲 BUG-#133: Fix co_varnames to only include parameters, not local variables

[FernandoCelmer]

Description

• dotflow/core/action.py — Fix _set_params to slice co_varnames[:co_argcount + co_kwonlyargcount] instead of using the full co_varnames tuple

Motivation and Context

co_varnames includes all local variables, not just parameters. A function with a local variable named initial_context or previous_context would be falsely detected as having those parameters, triggering incorrect context injection.

The fix also accounts for keyword-only parameters (def step(*, initial_context):) via co_kwonlyargcount.

Closes #133

Types of changes

• Bug fix (change that fixes an issue)
• New feature (change which adds functionality)
• Documentation

Checklist

• I have performed a self-review of my own code
• I have added tests that prove my fix is effective or that my feature works
• I have updated the CHANGELOG
• I have updated the documentation accordingly