fix(feishu): route topic messages to thread ids

[LeonSGP43]

What does this PR do?

Fixes Feishu topic-thread routing for P2P chats.

When a user sends a message from a Feishu topic thread inside a P2P chat, Hermes was creating a new outbound message with receive_id_type="chat_id" even when thread_id was present in metadata. That caused replies to appear in the main chat instead of the topic.

This change keeps the existing reply flow intact, but makes non-reply sends target thread_id whenever thread metadata is present.

Related Issue

Fixes #9916

Type of Change

• 🐛 Bug fix (non-breaking change that fixes an issue)
• ✨ New feature (non-breaking change that adds functionality)
• 🔒 Security fix
• 📝 Documentation update
• ✅ Tests (adding or improving test coverage)
• ♻️ Refactor (no behavior change)
• 🎯 New skill (bundled or hub)

Changes Made

• Route Feishu non-reply outbound messages to thread_id instead of chat_id when metadata["thread_id"] is present in gateway/platforms/feishu.py
• Preserve existing reply_to behavior and reply_in_thread handling for true reply sends
• Add a regression test that verifies new outbound topic messages use receive_id_type="thread_id" in tests/gateway/test_feishu.py

How to Test

1. Run source .venv/bin/activate && python -m pytest tests/gateway/test_feishu.py -q
2. Confirm the suite passes, including test_send_routes_new_message_to_thread_when_thread_metadata_present
3. In a Feishu P2P chat topic, send a message from inside the topic and confirm the bot reply lands in that topic rather than the main chat

Checklist

Code

• I've read the Contributing Guide
• My commit messages follow Conventional Commits (fix(scope):, feat(scope):, etc.)
• I searched for existing PRs to make sure this isn't a duplicate
• My PR contains only changes related to this fix/feature (no unrelated commits)
• I've run pytest tests/ -q and all tests pass
• I've added tests for my changes (required for bug fixes, strongly encouraged for features)
• I've tested on my platform: macOS 15.x

Documentation & Housekeeping

• I've updated relevant documentation (README, docs/, docstrings) — or N/A
• I've updated cli-config.yaml.example if I added/changed config keys — or N/A
• I've updated CONTRIBUTING.md or AGENTS.md if I changed architecture or workflows — or N/A
• I've considered cross-platform impact (Windows, macOS) per the compatibility guide — or N/A
• I've updated tool descriptions/schemas if I changed tool behavior — or N/A

Screenshots / Logs

• Targeted verification: tests/gateway/test_feishu.py -q → 107 passed
• I left the full-suite checkbox unchecked because local pytest tests/ -q currently has unrelated pre-existing failures on main