Improve deployment documentation with permission requirements

[krisoye]

Problem

The installation instructions in deploy/audio-analysis-mcp.service don't include complete permission setup steps, leading to deployment issues.

Current Documentation Gaps

1. Doesn't mention directory permissions for /etc/audio-analysis-mcp/
2. Doesn't include .env file permission requirements
3. Missing verification steps

Proposed Documentation Update

Update deploy/audio-analysis-mcp.service header:

# Installation:
#   1. Copy to /etc/systemd/system/audio-analysis-mcp.service
#   2. Modify paths and user as needed
#   3. Create credential directory and file for HuggingFace token:
#      sudo mkdir -p /etc/audio-analysis-mcp
#      sudo chmod 755 /etc/audio-analysis-mcp
#      echo "hf_YOUR_TOKEN" | sudo tee /etc/audio-analysis-mcp/hf_token > /dev/null
#      sudo chmod 600 /etc/audio-analysis-mcp/hf_token
#   4. Ensure .env file is readable by service user:
#      chmod 640 /home/deploy/prod/audio-analysis-mcp/.env
#      chown deploy:prod-readers /home/deploy/prod/audio-analysis-mcp/.env
#   5. sudo systemctl daemon-reload
#   6. sudo systemctl enable audio-analysis-mcp
#   7. sudo systemctl start audio-analysis-mcp
#
# Verification:
#   sudo systemctl status audio-analysis-mcp
#   curl http://localhost:8420/health
#   sudo journalctl -u audio-analysis-mcp -n 50

Additional Documentation Needed

Create docs/DEPLOYMENT.md with:

1. Pre-deployment checklist
2. Permission requirements table
3. Troubleshooting common issues
4. Rollback procedures

Labels

• P3-low - Enhancement, not blocking
• type:docs - Documentation improvement
• area:deployment - Deployment process