fix(feishu): add open group active context

[YuanHanzhong]

Summary

• allow Feishu group_rules[chat_id].policy=open to authorize human group messages without globally allowing every sender
• record recent human group messages in a bounded per-chat ring buffer and inject them as context-only channel_context for follow-up messages
• suppress human-to-human @mentions as observe-only unless the bot is addressed, while preserving them for later context
• persist explicit latest_by_chat.latest_purpose and updated_at state when a recent-context state path is configured

Related issues / prior art

• Related to [Feature]: Buffer unmentioned Feishu/Lark group messages and process them when the bot is mentioned #25728, but this supports active open-group replies instead of only buffering until a later bot mention.
• Complements Gateway mention gates can drop Feishu reply @mentions before hydration #21366 by preserving Feishu context around mention gates.
• I also noticed adjacent open Feishu group-rule PRs (fix(feishu): read group_policy from config extra + add WS fallback for group messages #44886, Feat/feishu: group chat allowlist #29709, fix(gateway/feishu): bridge yaml group_rules/admins/default_group_policy to extra #42790); this patch keeps the scope to authz + bounded observed context.

Validation

• /Users/xiashui/.hermes/hermes-agent/.venv/bin/python -m pytest tests/gateway/test_feishu_active_context.py tests/gateway/test_unauthorized_dm_behavior.py tests/gateway/test_feishu_bot_admission.py tests/gateway/test_feishu_bot_auth_bypass.py tests/gateway/test_feishu.py tests/gateway/test_text_batching.py::TestFeishuAdaptiveDelay -q => 269 passed / 45 skipped
• /Users/xiashui/.hermes/hermes-agent/.venv/bin/python -m compileall -q gateway/platforms/feishu.py tests/gateway/test_feishu_active_context.py gateway/authz_mixin.py tests/gateway/test_unauthorized_dm_behavior.py => PASS

Not included

• No gateway restart/reload behavior.
• No fast-ack/background follow-up scheduling; that belongs in the gateway run loop rather than the Feishu adapter.

[teknium1]

Thanks for the focused Feishu context work. This needs substantial rework for current main.

Problems

• The authorization change conflicts with the current fail-closed gateway contract: gateway/authz_mixin.py:467-514 intentionally does not trust group_policy: open, tests/gateway/test_config_driven_access_policy.py:212-220 locks that behavior down, and SECURITY.md:202-205 requires a caller allowlist for network-exposed adapters.
• The diff targets gateway/platforms/feishu.py, but 552adbe08 moved that adapter to plugins/platforms/feishu/adapter.py; it cannot be directly salvaged onto current main.
• PR commit ede51b731267 adds non-secret HERMES_FEISHU_RECENT_CONTEXT_* behavior settings. Repository policy requires this configuration to live in config.yaml.

Suggested changes

• Rework authorization without making policy: open a gateway caller-authorization bypass.
• Port the context work to plugins/platforms/feishu/adapter.py, make it opt-in via config.yaml, and add current-main integration coverage for authorization and channel_context delivery.
• Please align buffering semantics with canonical discussion [Feature]: Buffer unmentioned Feishu/Lark group messages and process them when the bot is mentioned #25728; Feishu group chat: add context from non-mentioned messages between bot interactions #55530 was explicitly redirected there.

Automated hermes-sweeper review.

[xy769]

Hi @YuanHanzhong — wanted to flag this PR as a real-world need: I'm running Hermes-Feishu in a 3-person work group where users frequently ask the bot to "summarize what we just discussed", and the bot currently has zero visibility into messages between @-mentions. Issue #25728 captures this same ask.

I read through the diff and the sweeper's three blockers carefully. They're all reasonable and I think they can be fixed in one pass without changing the design:

1. Path move. Commit 552adbe08 relocated the Feishu adapter from gateway/platforms/feishu.py to plugins/platforms/feishu/adapter.py. The 301-line buffer/ring-buffer logic in this PR needs to land in the plugin and re-attach to the new event dispatcher hooks in _handle_message_event_data / _process_inbound_message.

2. Config drift. HERMES_FEISHU_RECENT_CONTEXT_* should move to config.yaml per repo policy (CONTRIBUTING.md). Suggested schema:

   plugins:
     feishu:
       group_context:
         recent_buffer_size: 20          # 0 = off
         recent_buffer_ttl_seconds: 3600 # 1h
         deliver_on_mention: true

3. Authz narrowing. The change at gateway/authz_mixin.py currently lets policy: open on a group_rules entry bypass the gateway caller allowlist (SECURITY.md:202-205). Scoping this to per-chat authorization only — not caller-allowlist bypass — would preserve the fail-closed contract for network-exposed adapters.

Happy to send a port-PR against main that lands these three fixes plus the existing tests moved to the new layout, if useful. But no urgency — if you're mid-revision, please drive it. Just want to avoid stomping.