[Cloud] strip UTF-8 BOM from agent-seed.env

[GuillaumeDSM]

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Summary

Make the Cloud Agent install use the ui-node-web profile, and make .cursor/agent-seed.env sourceable by Bash.

Solve the issue: #___

Changelog

• Default environment.json install is PANTS_PANTSD=false OCTOBOT_CLOUD_PROFILE=ui-node-web bash .cursor/cloud-install.sh
• Strip the leading UTF-8 BOM from .cursor/agent-seed.env
• Document that GitHub cloud-env-validate still installs ci-tentacles

What's new?

Cloud agents that follow environment.json now build the node web UI (ui-node-web) instead of stopping at ci-tentacles. PANTS_PANTSD=false keeps the Pants daemon from reserving extra memory during install.

.cursor/agent-seed.env began with a UTF-8 BOM. Bash treated that byte as part of the first variable name, so source .cursor/agent-seed.env failed and bash .cursor/seed-agent.sh could not resolve user/agent-seed. The variable values are unchanged.

GitHub Actions cloud-env-validate still passes OCTOBOT_CLOUD_PROFILE=ci-tentacles itself.

Validation

Local ui-node-web install passed twice (OCTOBOT_CLOUD_INSTALL_OK). bash .cursor/cloud-validate.sh --profile ui-node-web --json passed. Simulated seed wrote user/agent-seed (Kraken sim accounts). Node UI login with passphrase demodemo showed Seed kraken A and Seed kraken B. Draft build bld-20261006-ca757bec-10d6-4724-8ad6-c0249b2814c5 (from dev) succeeded, and a fresh agent booted from that build passed version, tentacles, UI dist, and pytest tests/unit_tests/test_octobot_version.py (4 passed).