refactor: remove Ollama integration and unused AI configuration

- Remove src/models/ollama_client.py, embeddings.py, embeddings_ollama.py
- Remove model aliases and AI config from settings (both config.py files)
- Update health endpoints to only check database connectivity
- Update tests to reflect database-only health checks
- Update README, .env.example, and OIDC docstrings

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "core-api"
-version = "1.10.3"
+version = "1.10.4"
 description = "Core Code API - Infrastructure management and tools API"
 readme = "README.md"
 requires-python = ">=3.12"