Refresh E2E-tested JavaScript dependencies

[Matt (mattgotteiner)]

Summary

• refresh the demo JavaScript dependencies within the existing API generation
• regenerate a portable npm lockfile with no environment-specific registry URLs
• document the Node.js 22 runtime required by the refreshed Azure SDK dependency tree

Live E2E validation

Validated on Node.js 22 against existing Azure resources:

• clean dependency installation passed
• uploaded 108 documents successfully
• text, vector, and hybrid queries returned relevant results
• regenerated text-embedding-3-large embeddings at 3072 dimensions
• removed all temporary indexes and test objects after validation

Additional validation

• npm audit reports zero vulnerabilities for the demo project
• lockfile contains no environment-specific package-feed URLs

Deferred from this PR

The following upgrades were restored to main and are intentionally not included:

• data-chunking dependencies: LangChain notebook passed live testing, but the indexer notebook was blocked by the existing shared-key-disabled/NSP Storage route
• custom-vectorizer dependencies: no existing Function App resources were available and provisioning was prohibited
• Document Intelligence custom-skill dependencies: no existing Document Intelligence/Function resources were available and provisioning was prohibited
• root dotenv update: not covered by the completed live E2E lane

These deferred upgrades require a future fully provisioned E2E hill before inclusion.