Update all documentation to use run/Runner terminology
Rename predict concepts to run across all user-facing and internal docs:
- README.md, docs/README.md: run.py:Runner, cog run, BaseRunner
- docs/python.md: ~40 substitutions (BaseRunner, def run(), Runner class)
- docs/getting-started.md, docs/getting-started-own-model.md
- docs/yaml.md: renamed 'predict' config section to 'run'
- docs/http.md: predict function → run function
- docs/training.md: BaseRunner, cog run
- docs/notebooks.md: run.py, BaseRunner
- docs/wsl2/wsl2.md: cog run
- CONTRIBUTING.md: run.py:Runner, pkg/run/
- AGENTS.md: updated project structure descriptions
- crates/README.md: PythonRunner, run() method
- architecture/*.md (11 files): updated diagrams and descriptions
Preserved as-is: 'prediction' as a noun, /predictions HTTP endpoints,
predict_time metric, predictor_ref protocol field, Config.Predict Go field.
