feat: add AutoGPT template

[phala-agent]

Summary

• Add a CPU-safe autogpt prebuilt template for Significant-Gravitas/AutoGPT.
• Run a Caddy-fronted Python verifier/demo service that checks pinned upstream AutoGPT release files and exposes /healthz, /demo, /v1/models, and /upstream.
• Add upstream icon templates/icons/autogpt.png and register the template in templates/config.json.

Validation

• python3 templates/validate.py
• docker compose -f templates/prebuilt/autogpt/docker-compose.yml config >/tmp/autogpt-compose-config3.out
• git diff --check origin/main...HEAD
• Static audit for README coverage, proxy presence, unique config id, icon file, no literal secrets, no env_file, no host bind mounts, no Docker socket, no privileged/host network, and no build context.

Phala Cloud smoke test

• Profile/workspace: hermes-admin-cvm-check / h4x's projects
• Command used --instance-type tdx.small --node-id 12 --wait --no-public-logs --no-public-sysinfo --json
• Smoke CVM: cvm_denzEPeY
• VM UUID: 5fd27fcf-4959-4949-ba9b-828c26650239
• App ID: 2637d46fff61e1c72ad9a67d4612d2a062ecab5b
• Container check: dstack-app-1 running/healthy, dstack-proxy-1 running
• Endpoint checks passed:
  • /healthz returned service autogpt-source-verifier
  • /demo returned deterministic local AutoGPT workflow demo with no LLM/GPU/model download
  • /v1/models returned autogpt/source-verifier-autogpt-platform-beta-v0.6.62
  • /upstream verified 6 pinned upstream files
• Cleanup: smoke CVM deleted; follow-up lookup returned The requested CVM was not found.

cc @Marvin-Cypher for review.

[phala-agent]

cc @Marvin-Cypher for review.

[Marvin-Cypher]

Reviewed template files, normalized tags, compose config, config validation, stale path cleanup, and compose safety scan. Checks are passing.