chore: Remove test files - insights moved to PR comments

Removed standalone test files as requested:
- demo_configurable_batch_size.py
- INTEGRATION_TEST_REPORT.md
- MEMORY_OPTIMIZATION_PROPOSAL.md
- test_embed_stream_comprehensive.py
- test_oci_embed_stream.py
- test_sdk_embed_stream_unit.py

Added .venv/ to .gitignore to prevent accidental commits.

All testing insights and findings have been documented in PR comments.

Author: fede-kamel

.gitignore

@@ -3,3 +3,4 @@
 __pycache__/
 dist/
 poetry.toml
+.venv/