Research: choose cloud provider (Railway vs Fly vs Render)

[krapfj23]

Summary

Evaluate cloud providers and recommend one for deploying the Cortex backend.

Blocked by

Nothing — this is a starting ticket.

Blocks

• Deploy to cloud + configure env vars #60 (deploy to cloud)

Steps

1. Evaluate Railway, Fly.io, and Render on: free tier limits, Docker support, PostgreSQL add-on (pgvector), persistent volumes (for Kuzu), env var management, deploy-from-GHCR support
2. Test deploying a minimal FastAPI container on the top 2 candidates
3. Compare cold start times, ease of setup, and pricing beyond free tier
4. Write findings to docs/cloud-provider-research.md with a recommendation

Acceptance Criteria

• docs/cloud-provider-research.md exists with comparison table
• At least 2 providers tested with a real container
• Clear recommendation with reasoning
• PR body includes Closes #59