fix(discord): allow category-scoped channel policies

[KLIEBHAN]

Summary

• Include Discord category IDs in the channel policy scope used by allowed, ignored, and free-response channel checks.
• Reuse one helper across message handling, no-mention filtering, and slash-command authorization.
• Add regression coverage for category-based free responses and slash-command allow/ignore policy.

Motivation

Discord text channels expose their containing category as category_id, while threads expose their parent channel through parent or parent_id. Existing channel policy checks only considered the concrete channel ID and, in some paths, a thread parent ID. That meant deployments could allow a thread parent or single channel, but could not reliably target a whole category with DISCORD_ALLOWED_CHANNELS or DISCORD_FREE_RESPONSE_CHANNELS.

Tests

python -m pytest tests/gateway/test_discord_free_response.py tests/gateway/test_discord_slash_auth.py

Result: 78 passed.

[teknium1]

Thanks for the focused Discord policy coverage. The category-ID gap is still present on current main: plugins/platforms/discord/adapter.py:4914-4945 builds the shared channel keys from channel ID/name/#name and parent scope, but not category_id.

Problems

• The current shared key mechanism supersedes the PR's standalone _discord_channel_scope_ids approach. A salvage should preserve the current ID/name/#name/parent matching contract used by normal messages at plugins/platforms/discord/adapter.py:6170-6198 and slash authorization at :3444-3472.
• Current fail-closed message authorization passes only channel and parent IDs into _is_allowed_user at plugins/platforms/discord/adapter.py:1151-1163; category-only DISCORD_ALLOWED_CHANNELS must be included there or normal messages are denied before _handle_message.
• The new free-response test exercises _handle_message, not the earlier no-mention admission filter changed by the PR. Add an end-to-end category case for that gate, plus a thread-under-category case.

Suggested changes

• Rework the patch against the shared channel-key resolver and cover all authorization paths above.
• Update website/docs/user-guide/messaging/discord.md:283-289 if category IDs are intentionally accepted in the existing channel-list settings. #61593 proposes a different explicit-category API, so maintainers should select the intended configuration shape.

Automated hermes-sweeper review.

[teknium1]

Current main now centralizes channel policy matching in _discord_channel_keys_from_channel() (adapter.py:4914-4945) and includes channel names, #name, and parent names. Please salvage category scope through that shared resolver rather than introducing a parallel ID-only key set, so all existing policy forms retain parity.

[KLIEBHAN]

Thanks for the detailed review. I rebased the PR onto current main and reworked the salvage around the shared channel-key resolver.

• Category IDs are now added in _discord_channel_keys_from_channel() for both direct channels and threads via their parent channel; the existing ID/name/#name/parent keys remain unchanged.
• The earlier fail-closed on_message authorization and the no-mention admission filter now both use the shared resolver.
• Slash allow/ignore authorization continues to use that same resolver, including category scope.
• Uncached discord.Thread instances now retain thread/parent policy keys instead of raising when Thread.category_id cannot resolve its parent from the guild cache.
• Added event-admission tests for a category channel and a thread under that category, downstream free-response coverage for a thread under a category, shared-key coverage, and discriminating slash allow/ignore tests.
• Updated both the environment-variable table and detailed config.yaml documentation for category IDs in the existing channel-list settings.

Targeted result: 138 passed (test_discord_connect.py, test_discord_free_response.py, test_discord_slash_auth.py, and test_discord_prompt_content_siblings.py). A real discord.py==2.7.1 uncached Thread smoke test also passes.

[GottZ]

This was generated by AI during triage.

Summary

Two PRs are included in this complex, but their diffs address separate Discord gaps: #54338 adds category-scoped channel-policy resolution, while #65931 adds searchable /model autocomplete. Neither diff implements the other's reported functionality.

Related pull requests

• #54338 related — (+291/-36) — keep open with a salvage path: The diff adds category IDs to the shared channel-key resolver and applies that resolver to early message authorization, no-mention admission, downstream message handling, and slash authorization, with direct-channel, thread-under-category, uncached-thread, allowlist, ignorelist, and documentation coverage. This preserves the salvage path identified by the contributor keep_open review on #54338 and directly addresses its stated concerns about the shared ID/name/#name/parent contract and the earlier admission gates.
• #65931 related — (+269/-1) — keep open with a salvage path: The isolated diff adds authorized, thread-offloaded, searchable /model autocomplete, preserves representable model values verbatim, skips overlong values, and tests filtering, limits, authorization, and provider-qualified values. This follows the contributor keep_open review on #65931: the current diff no longer contains the cited unrelated changes, and it addresses the value-truncation objection with discriminating regression coverage.

Suggested consolidation

Keep both PRs open on separate salvage paths rather than consolidating them as duplicates: retain #54338 for category-scoped Discord channel policies and #65931 for searchable /model autocomplete. The diffs are functionally independent, both now address the blocking concerns recorded in their respective contributor keep_open reviews, and there is no evidence that either is already implemented on main or duplicates the other.

Cross-PR triage: Reviewed 2 pull requests and 0 issues in this complex. Each diff was read against this issue; Assessment working set: 41 kB of PR diffs, 1 kB of issue/PR text, 6 kB of discussion (5 comments), 0 verify verdicts. verdicts reflect diff content, not PR titles. Part of an automated triage batch.

[andrexibiza]

Scope note (dedup-campaign triage, 2026-08-03): this PR covers category scoping for allowed/ignored/free-response policies. The canonical feature request (#38539) also requires require_mention_categories — the key that makes "free everywhere except category C" expressible. The complete three-key implementation shipped in #77380; PR bodies reference Fixes #38539, so merging #77380 closes the issue. No action needed on this PR beyond a maintainer consolidation call.