bug: config set treats negative numeric values as CLI flags #45

Description

Running mlx-stack config set memory-budget-pct -5 produces:

Error: No such option: -5

Click interprets -5 as a CLI flag instead of a value argument. This is a known Click limitation when positional arguments start with -.

Steps to Reproduce

mlx-stack config set memory-budget-pct -5
# Expected: "Invalid memory budget '-5'. Must be between 1 and 100."
# Actual: "Error: No such option: -5"

Expected Behavior

Negative values should be passed through to the validation layer, which already correctly rejects out-of-range values (tested: 200 correctly produces "Must be between 1 and 100").

Possible Fixes

1. Use Click's nargs or type handling to prevent flag interpretation
2. Add context_settings=dict(ignore_unknown_options=True)
3. Document that -- separator can be used: mlx-stack config set -- memory-budget-pct -5

Impact

Low — edge case, but the error message is confusing and misleading.