fix(discord): mention user in approval/clarify prompts for notification ping

[nanobro]

What

When Hermes needs user approval on Discord, it now mentions the user (<@USER_ID>) so they get a native Discord notification ping instead of silently waiting in a thread.

Problem

Approval/clarify prompts were sent into threads without any mention. Users would miss requests entirely because there was no notification.

Solution

• Added user_mention parameter to 4 Discord adapter methods:

  • send_exec_approval() — dangerous command approval
  • send_slash_confirm() — expensive slash command confirmation
  • send_clarify() — agent clarification prompts
  • send_update_prompt() — gateway update input

• Gateway builds <@user_id> mention for Discord platform only (other platforms unaffected)

• Mention is prepended to embed description, triggering Discord's native ping

Files Changed

File	Change
gateway/run.py	Build _user_mention in 3 callback functions
plugins/platforms/discord/adapter.py	Accept and prepend user_mention in 4 send methods
docs/howto-discord-approval-notify.md	Community how-to documentation

Testing

• ✅ Syntax check passed (py_compile)
• ✅ No secrets/credentials in diff
• ✅ Gateway restarted successfully with changes

[teknium1]

Thanks for targeting a real notification gap. Current main still defaults to no exec-approval mention and does not mention users for slash confirmations, clarify prompts, or update prompts.

Problems

• The new user_mention keyword is passed from generic gateway paths in gateway/run.py:10713, :13986, and :14112, including non-Discord adapters. Current shared adapter contracts such as gateway/platforms/base.py:3076-3084 do not accept it, so this can turn native prompt rendering into a TypeError fallback.
• The adapter changes put mentions only in embed descriptions. Current main's accepted exec-mention implementation places the mention in plain message content and configures AllowedMentions (plugins/platforms/discord/adapter.py:5609-5611, :5647-5657). The sibling prompts now also use content mirrors (:5691-5702, :5823-5827, :5864-5869), so the patch needs to target those paths.
• No regression tests accompany the four changed send methods or the cross-platform gateway contract.

Suggested changes

• Keep the Discord-specific data out of generic adapter calls unless the common contract is intentionally extended and all implementations are covered.
• Build on the current content-mirror and opt-in mention mechanism, then add focused Discord and non-Discord dispatch tests.

Automated hermes-sweeper review.

[teknium1]

This call is generic: non-Discord adapters are invoked too, but their shared send_slash_confirm contract has no user_mention keyword (gateway/platforms/base.py:3076-3084). Passing it even as None can raise TypeError and discard the native-button path. Scope this argument to Discord or extend the contract consistently.

[teknium1]

Current main sends interactive-prompt payloads in ordinary content as well as embeds, and its existing exec-approval mention path prepends the mention to that content with scoped AllowedMentions. Put the notification marker in the content mirror rather than only this embed description.

[doryani-ai]

Thanks for identifying the exact four-prompt notification gap, @nanobro. I reproduced it in production and opened #82982 as a current-main successor after this branch remained conflicted and the July review feedback was unresolved. The new PR credits you as co-author, preserves this PR's scope, and builds on the merged opt-in content-mirror/AllowedMentions design from #60493. It also adds multiplex-profile isolation, exact owner-only AllowedMentions, a bounded large-allowlist path, focused regression coverage, and docs. Maintainers can use whichever contribution path they prefer.