Add integration tests for all examples

[ppiegaze]

Summary

• Expand integration tests from 7 to 52 test functions covering all runnable examples
• Add pytest markers for selective test execution (apps, gpu, external, stress, secrets)
• Add _deploy_and_verify() helper for app deployment tests

Test Categories Added

Category	Tests	Notes
Basics - Core	3	hello, file, directory (existing)
Basics - Additional	10	map, enum_vals, frames, etc.
Types	2	simple_types, dataclass_types
Advanced	7	display_names, custom_context, multi_loops, etc.
ML	3	model_training, rfe, distributed_random_forest
Reports	1	streaming_reports
Streaming	1	basic_as_completed
Sync	1	async_in_sync
Reuse	1	reusable
Caching	1	content_based_caching
GenAI	1	hello_agent
Data Processing	1	deltalake
Plugins	4	spark, ray, dask, pytorch (existing)
Apps (deploy)	2	basic_app, single_script_fastapi
GPU (skipped)	4	accelerators, gridsearch, vllm, sglang
External (skipped)	2	bigquery, databricks
Secrets (skipped)	3	openai_agent, langgraph, wandb
Stress (skipped)	5	large_fanout, long_running, etc.

Total: 52 tests (36 active, 16 skipped)

Test Execution Tiers

# Tier 1: Core tests (every PR) - ~34 tests
pytest -m "integration and not (gpu or external or stress or apps or secrets)"

# Tier 2: Including apps (nightly) - ~36 tests
pytest -m "integration and not (gpu or external or stress or secrets)"

# Tier 3: GPU tests (weekly, GPU runners)
pytest -m "integration and gpu"

# Tier 4: All tests (manual)
pytest -m "integration"

Test plan

• Verify syntax check passes: python3 -m py_compile examples/integration_tests.py
• Run Tier 1 tests on PR CI
• Verify pytest markers are recognized

🤖 Generated with Claude Code