fix(discord): add config-backed auto-thread channels

[jeeves-assistant]

Summary

• Reworks the original env-only DISCORD_FORCE_AUTO_THREAD_CHANNELS patch into the config-first shape proposed by fix: restored Discord free-response auto-thread override #27651: discord.auto_thread_channels / DISCORD_AUTO_THREAD_CHANNELS.
• Allows selected discord.free_response_channels to still auto-create per-conversation threads for top-level posts.
• Keeps discord.no_thread_channels as the stronger hard opt-out.
• Ports the behavior to the current bundled Discord plugin (plugins/platforms/discord/adapter.py), adds default config/example/docs coverage, and documents the relation to free-response auto-threading.
• Refreshed the branch against current upstream main after the Discord channel-key matching changes; auto_thread_channels now participates in the same ID/name/#name key matching path as the other Discord channel gates.

Relationship to #27651

This PR is intentionally the current-codebase port/synthesis of the older #27651 idea. #27651 had the better API shape (discord.auto_thread_channels) but targeted stale Discord paths; this branch now applies that design to the current plugin implementation.

Tests

• python -m py_compile plugins/platforms/discord/adapter.py hermes_cli/config.py
• python -m pytest tests/gateway/test_discord_channel_controls.py tests/gateway/test_discord_free_response.py tests/gateway/test_discord_slash_auth.py -q -o 'addopts='
• python -m pytest tests/gateway/test_discord_edit_message_overflow.py tests/gateway/test_discord_pending_text_batch_shutdown.py tests/gateway/test_typing_indicator_toggle.py -q -o 'addopts='
• git diff --check

[alt-glitch]

This was generated by AI during triage.

Duplicate of #49726 — verified same mechanism: this adds a DISCORD_FORCE_AUTO_THREAD_CHANNELS set and rewrites skip_thread = ... or (is_free_channel and not force_thread) in plugins/platforms/discord/adapter.py, identical to #49726's force_thread_channels knob (the earliest open/canonical PR in this cluster, with tests). #52718 was already marked a duplicate of #49726. #52802 takes a different config knob (free_response_thread_channels) and is a related competing approach, not the same mechanism. Tracking the auto-thread-for-free-response feature under #49726.

[jeeves-assistant]

Updated this PR so it no longer carries the Rob-specific/env-only DISCORD_FORCE_AUTO_THREAD_CHANNELS shape. It now implements the older #27651 design as discord.auto_thread_channels / DISCORD_AUTO_THREAD_CHANNELS in the current bundled Discord plugin, with docs and config-bridge coverage. That makes this PR a current-codebase port/synthesis of #27651 rather than a separate competing API.

[alt-glitch]

This was generated by AI during triage.

Related to #49726, but not a duplicate after the update: this branch now implements the config-first discord.auto_thread_channels contract on the current plugin path rather than the earlier env-only force_thread_channels approach.

[Enough1122]

AI code review — automated review for reference, author can ignore or act on any point.

fix(discord): add config-backed auto-thread channels

1. plugins/platforms/discord/adapter.py (_handle_message, ~line 8145-8147): the "*" in auto_thread_channels wildcard is the documented headline feature but has no test coverage — only exact-channel-ID cases are pinned (test_auto_thread_channel_overrides_free_response). Please add a "*" test that also asserts no_thread_channels still wins as the hard opt-out.
2. Dual source-of-truth precedence is subtle: _discord_auto_thread_channels() reads self.config.extra first, but the YAML path never populates extra["auto_thread_channels"] — _apply_yaml_config bridges YAML → DISCORD_AUTO_THREAD_CHANNELS env var, so YAML-configured deployments always take the env fallback; the extra branch only fires when PlatformConfig is built with an explicit extra= dict (i.e., in tests). It works, but consider collapsing to a single source so the two paths can't drift.
3. Minor: force_auto_thread is computed for every incoming message even when the channel is not a free-response channel (where the value is irrelevant). Computing it lazily inside the is_free_channel branch would make the intent clearer.

[alt-glitch]

This was generated by AI during triage.

Related to #27651 and #82354: this revised PR adds the distinct config-backed auto_thread_channels behavior and is no longer the former env-only duplicate of closed #49726.

[alt-glitch]

This was generated by AI during triage.

Related: this refreshed config-backed discord.auto_thread_channels implementation differs from closed #49726's env-only force_thread_channels approach, and overlaps the broader threading-semantics change in #82354. It is not marked duplicate.