[cofin]

Summary

Repairs outdated configuration, installation, and provider documentation across docs/getting-started/ and docs/supported-databases/, removing stale Docker Compose environment variables (SKIP_DOCKER_COMPOSE, USE_LEGACY_DOCKER_COMPOSE), fixing broken class/fixture references (AzureBlobService, dragonfly_*, minio_service, elasticsearch), and documenting Docker/Podman runtime resolution, deterministic session ownership, and pytest-xdist isolation modes.

Key Changes

Getting Started Documentation (docs/getting-started/)

• Runtime & Session Configuration (docs/getting-started/configuration.rst): Removes obsolete Docker Compose references and documents --container-runtime (auto, docker, podman), --container-runtime-path, --container-host, --session-id / PYTEST_DATABASES_NAMESPACE, and xdist_<backend>_isolation_level fixtures.
• Installation & Clientless Usage (docs/getting-started/installation.rst, docs/getting-started/basic-usage.rst): Documents clientless *_service readiness validation and lists all supported compatibility extras (postgres, alloydb, mysql, mariadb, dolt, oracle, mssql, spanner, bigquery, cockroachdb, yugabyte, mongodb, gizmosql, redis, valkey, elasticsearch, azure-blob, minio, rustfs).

Supported Databases Documentation (docs/supported-databases/)

• Azure Blob Storage & Redis (azure_blob_storage.rst, redis.rst): Fixes AzureBlobService class/fixture names and dragonfly_* fixture references.
• MinIO, RustFS & Elasticsearch (minio.rst, rustfs.rst, elasticsearch.rst): Updates Chainguard MinIO images (cgr.dev/chainguard/minio:latest and cgr.dev/chainguard/minio-client:latest), removes unimplemented environment variable claims, and updates pytest-databases[elasticsearch] usage examples.
• Oracle & Spanner (oracle.rst, spanner.rst): Documents xdist_oracle_isolation_level and xdist_spanner_isolation_level ("database" vs "server").

Closes #109
Closes #146