docs: update artifact-keeper-site for Meilisearch to OpenSearch migration

[brandonrc]

Context

The OpenSearch migration (#462, PR #830) replaces Meilisearch with OpenSearch. The documentation site has 13+ files referencing Meilisearch that need updating.

Files to Update

• getting-started/configuration.mdx - MEILISEARCH_URL/API_KEY env vars -> OPENSEARCH_*
• getting-started/quickstart.mdx - Services list
• getting-started/installation.mdx - Container image, port 7700 -> 9200
• getting-started/architecture.mdx - Architecture diagrams
• deployment/docker.mdx - Service definitions, troubleshooting sections, health checks
• deployment/helm.mdx - Chart description
• deployment/aws.mdx - Diagram nodes
• deployment/windows.mdx - Optional services section
• index.mdx - Feature list
• package-formats.mdx - Search reference
• cli/tui.mdx - Search endpoint reference
• advanced/edge-nodes.mdx - Diagram node

Changes Required

• Replace "Meilisearch" with "OpenSearch" throughout
• Update port references from 7700 to 9200
• Update env var names (MEILISEARCH_* -> OPENSEARCH_*)
• Update container image references (getmeili/meilisearch -> opensearchproject/opensearch)
• Update health check URLs (/health -> /_cluster/health)
• Update troubleshooting sections (LMDB -> Lucene, memory sizing)