Add skill selection layer with constrained choices (no free-form skills) #15
Description
Agents must select skills from a predefined registry instead of defining arbitrary capabilities.
Goals:
- prevent unnecessary or irrelevant skill usage
- reduce prompt/context noise
- improve execution precision
Features:
- dropdown/selection-based skill assignment
- validation against registry
- optional skill activation per task/session
Behavior:
- agent chooses only relevant skills
- system restricts execution scope to selected skills