Enable automatic deletion of merged branches

[Paladin173]

Summary

The repository does not currently delete merged pull-request branches automatically:

• GET /repos/hermes-webui/hermes-android reports delete_branch_on_merge: false.
• The setting was identified as an admin-only follow-up while completing PR Make CI checks safe to require on main #102, but it was left only in the implementation chat and a local ignored payload.
• No existing open or closed issue tracks it.

This issue makes that unresolved repository-setting change durable and independently verifiable.

Proposed completion

Enable Automatically delete head branches under Settings > General > Pull Requests, or apply the equivalent API update:

PATCH /repos/hermes-webui/hermes-android
{"delete_branch_on_merge": true}

Repository Admin permission is required. The current Paladin173 access level is Maintain, so an organization owner or repository administrator must either apply the setting or grant the necessary role.

Verification

1. Read back GET /repos/hermes-webui/hermes-android and confirm delete_branch_on_merge: true.
2. Merge a disposable or ordinary pull request whose branch is hosted in this repository.
3. Confirm GitHub deletes the merged head branch while leaving fork-owned branches unaffected.

Related operational follow-up: #105.

[Paladin173]

Outcome

Automatic merged-branch deletion will remain disabled. It is optional rather than a repository requirement, and the current Maintainer role cannot change this Admin-only setting.

Manual cleanup remains the policy when branch state can be verified safely. In this pass:

• local main was fast-forwarded to current origin/main;
• five merged local branches were removed after their exact pull-request head SHAs and merged states were verified;
• the merged remote docs/issue-comment-accountability branch was removed after its SHA was matched to PR Require issue resolution comments before closure #104;
• worktree-bound branches and a branch containing commits beyond its merged pull request were preserved.

Final verification showed a clean, synchronized main. No source files or repository settings changed.