test: rename predict->run in integration tests
Mechanical find-and-replace across ~143 files:
- cog predict -> cog run
- predict.py:Predictor -> run.py:Runner
- BasePredictor -> BaseRunner
- class Predictor -> class Runner
- def predict -> def run
- predict: -> run: in cog.yaml
- Updated comments and variable names
Edge cases preserved:
- predict_time metric name (unchanged)
- /predictions API path (unchanged)
- prediction as a noun in comments (unchanged)
- OpenAPI schema assertions with server-generated content (unchanged)
- Source: comments referencing original test file names (unchanged)
