Add Harn

[kennethsinder]

Summary

Adds Harn to the ACP Agent Registry using the v0.8.133 GitHub release binaries for macOS, Linux, and Windows.

Harn serves ACP over stdio with:

harn serve acp

Validation

Ran against this branch:

uv run --with jsonschema .github/workflows/build_registry.py --dry-run
python3 .github/workflows/verify_agents.py --auth-check --agent harn --auth-timeout 120 --verbose

The auth check downloaded the v0.8.133 darwin-aarch64 archive and passed with:

Auth OK: none(agent)

[kennethsinder]

Quick bump on this registry submission. The PR body has the validation commands and auth-check result; happy to adjust the manifest if anything is missing.

[kennethsinder]

Updated the Harn entry to v0.8.158 and refreshed all binary archive URLs to the latest published Harn release.

Validation rerun from this branch:

uv run --with jsonschema .github/workflows/build_registry.py --dry-run
python3 .github/workflows/verify_agents.py --auth-check --agent harn --auth-timeout 120 --verbose

Result: registry dry-run validated 39 agents successfully and the focused Harn auth check downloaded the v0.8.158 darwin-aarch64 archive and passed with Auth OK: none(agent).

[kennethsinder]

Refreshed Harn to v0.9.15 in 0522564.\n\nValidation from the refreshed branch:\n\nbash\nuv run --with jsonschema .github/workflows/build_registry.py --dry-run\npython3 .github/workflows/verify_agents.py --auth-check --agent harn --auth-timeout 120 --verbose\n\n\nResults:\n\ntext\nDry run: validated 39 agents successfully\nharn v0.9.15\nAuth OK: none(agent)\nPassed: 1, Failed: 0, Skipped: 0\n

[kennethsinder]

Refreshed the Harn entry to the current v0.9.17 release assets in commit db5ebde.

Validation run on this branch:

uv run --with jsonschema .github/workflows/build_registry.py --dry-run
python3 .github/workflows/verify_agents.py --auth-check --agent harn --auth-timeout 120 --verbose

Results:

Dry run: validated 39 agents successfully
harn: Auth OK: none(agent)
Passed: 1, Failed: 0, Skipped: 0