feat(gateway): opt-in Discord requester mention on approval prompts

[donovan-yohan]

Summary

Adds an opt-in Discord setting, discord.mention_exec_approval / DISCORD_MENTION_EXEC_APPROVAL, default false.

When enabled, dangerous-command approval prompts on Discord prepend <@user_id> command approval needed so the original requester gets notified while the agent is blocked waiting for approval.

The mention is constrained to a digit-only requester ID and the outgoing approval message uses per-message AllowedMentions restricted to that single user. @everyone, @here, role pings, and replied-user pings remain disabled.

Configuration

discord:
  mention_exec_approval: true

DISCORD_MENTION_EXEC_APPROVAL=true

If both are present, the environment variable wins. Blank or invalid env values stay disabled.

Implementation

• Reads the YAML setting into Discord platform extra; does not seed process env from YAML, so gateway config reloads cannot get stuck behind a self-written env var.
• Adds approval-only metadata containing requester_user_id for Discord human requesters.
• Keeps normal status/progress metadata generic (thread_id, Telegram DM topic fallback, Feishu reply metadata).
• send_exec_approval() adds mention content only when the setting is enabled and the requester ID is digit-only.

Verification

• ulimit -n 4096 && ./scripts/run_tests.sh tests/gateway/test_config.py tests/gateway/test_discord_send.py tests/gateway/test_status_thread_metadata.py -q — 87 passed
• ulimit -n 4096 && ./scripts/run_tests.sh tests/gateway/test_tts_media_routing.py -q — 6 passed
• git diff --check upstream/main...HEAD
• conflict-marker scan over changed files

Full tests/gateway -q was also attempted locally: the PR-relevant suites passed, while the run still had unrelated existing/baseline failures around Platform.GOOGLE_CHAT plugin enum registration plus two parallel timing failures that passed when rerun in isolation.

Risk

Low: default off, requester IDs are validated before mention construction, and the mention allowlist is scoped per approval message.

[Copilot]

Pull request overview

Adds an opt-in Discord feature to @mention the original requester when a dangerous-command execution approval prompt is posted, improving responsiveness (especially for mobile users) while keeping mentions tightly scoped via per-message allowed_mentions.

Changes:

• Introduces discord.mention_exec_approval / DISCORD_MENTION_EXEC_APPROVAL (default false) and wires it through config/env bridging.
• Refactors status/approval metadata construction into gateway.run._build_status_thread_metadata, adding Discord requester fields while preserving Feishu reply-in-thread behavior.
• Updates Discord adapter send_exec_approval() to conditionally prepend a validated <@user_id> mention and pin allowed_mentions to that single user; adds/extends tests and documentation.

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
gateway/run.py	Extracts status/approval metadata builder and enriches metadata for Discord/Feishu.
gateway/platforms/discord.py	Adds config reader + mention/allowed_mentions behavior in exec approval sends.
gateway/config.py	Bridges discord.mention_exec_approval from YAML to adapter extra and env var.
tests/gateway/test_status_thread_metadata.py	Adds focused unit tests for the new metadata builder behavior.
tests/gateway/test_discord_send.py	Adds tests covering ping-enabled/disabled paths and invalid requester ID handling.
tests/gateway/test_config.py	Adds tests for YAML→env bridging and env precedence.
tests/gateway/conftest.py	Extends the shared Discord mock to support embed fields and allowed-mentions assertions.
website/docs/user-guide/messaging/discord.md	Documents the new Discord setting and behavior.
website/docs/reference/environment-variables.md	Documents the new env var and links to the Discord docs section.

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[donovan-yohan]

Rebased/resolved conflicts against current main and force-updated the PR branch.

Follow-up fixes included:

• preserved upstream Telegram DM topic fallback metadata during conflict resolution
• fixed DISCORD_MENTION_EXEC_APPROVAL precedence so an explicit env var overrides YAML
• tightened default-off boolean parsing so blank/invalid values do not enable pings
• kept Discord approval send tests robust when ExecApprovalView is absent under faked discord imports
• fixed the post-stream media helper fallback surfaced by the full gateway suite

Verification:

• ulimit -n 4096 && pytest tests/gateway/test_discord_send.py tests/gateway/test_status_thread_metadata.py tests/gateway/test_config.py tests/gateway/test_tts_media_routing.py -q — 85 passed
• ulimit -n 4096 && pytest tests/gateway -q — 5243 passed, 10 skipped
• git diff --check nous/main...HEAD
• conflict-marker scan clean

Current head: 50d4d6662c300a65c4266f3ba49baa4be1785176

[Copilot]

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[Copilot]

Pull request overview

Copilot reviewed 9 out of 9 changed files in this pull request and generated 1 comment.

[donovan-yohan]

Rebased against current main and force-updated the PR branch.

Follow-up cleanup:

• resolved merge conflicts while preserving upstream Discord thread mention gating, Telegram DM topic fallback, and Feishu topic reply metadata
• removed the YAML→env self-seeding path for DISCORD_MENTION_EXEC_APPROVAL so config reloads cannot get stuck behind a process env var written by the loader
• kept requester metadata approval-only and reduced it to requester_user_id
• removed noisy inline rationale comments / misleading AllowedMentions wording
• dropped an unrelated post-stream media helper fallback from this PR

Verification:

• ulimit -n 4096 && ./scripts/run_tests.sh tests/gateway/test_config.py tests/gateway/test_discord_send.py tests/gateway/test_status_thread_metadata.py -q — 87 passed
• ulimit -n 4096 && ./scripts/run_tests.sh tests/gateway/test_tts_media_routing.py -q — 6 passed
• git diff --check upstream/main...HEAD
• conflict-marker scan over changed files

GitHub now reports mergeable: MERGEABLE at head 570b69f577bb88928ea703cd8d82c73ffc6ce68e.