feat(gateway): add Feishu/Lark platform support (#3817)

Adds Feishu (ByteDance's enterprise messaging platform) as a gateway
platform adapter with full feature parity: WebSocket + webhook transports,
message batching, dedup, rate limiting, rich post/card content parsing,
media handling (images/audio/files/video), group @mention gating,
reaction routing, and interactive card button support.

Cherry-picked from PR #1793 by penwyp with:
- Moved to current main (PR was 458 commits behind)
- Fixed _send_with_retry shadowing BasePlatformAdapter method (renamed to
  _feishu_send_with_retry to avoid signature mismatch crash)
- Fixed import structure: aiohttp/websockets imported independently of
  lark_oapi so they remain available when SDK is missing
- Fixed get_hermes_home import (hermes_constants, not hermes_cli.config)
- Added skip decorators for tests requiring lark_oapi SDK
- All 16 integration points added surgically to current main

New dependency: lark-oapi>=1.5.3,<2 (optional, pip install hermes-agent[feishu])

Fixes #1788

Co-authored-by: penwyp <penwyp@users.noreply.github.com>

gateway/run.py

@@ -983,6 +983,7 @@ class GatewayRunner:
                        "EMAIL_ALLOWED_USERS",
                        "SMS_ALLOWED_USERS", "MATTERMOST_ALLOWED_USERS",
                        "MATRIX_ALLOWED_USERS", "DINGTALK_ALLOWED_USERS",
+                       "FEISHU_ALLOWED_USERS",
                        "GATEWAY_ALLOWED_USERS")
         )
         _allow_all = os.getenv("GATEWAY_ALLOW_ALL_USERS", "").lower() in ("true", "1", "yes") or any(
@@ -991,7 +992,8 @@ class GatewayRunner:
                        "WHATSAPP_ALLOW_ALL_USERS", "SLACK_ALLOW_ALL_USERS",
                        "SIGNAL_ALLOW_ALL_USERS", "EMAIL_ALLOW_ALL_USERS",
                        "SMS_ALLOW_ALL_USERS", "MATTERMOST_ALLOW_ALL_USERS",
-                       "MATRIX_ALLOW_ALL_USERS", "DINGTALK_ALLOW_ALL_USERS")
+                       "MATRIX_ALLOW_ALL_USERS", "DINGTALK_ALLOW_ALL_USERS",
+                       "FEISHU_ALLOW_ALL_USERS")
         )
         if not _any_allowlist and not _allow_all:
             logger.warning(
@@ -1434,6 +1436,13 @@ class GatewayRunner:
                 return None
             return DingTalkAdapter(config)
 
+        elif platform == Platform.FEISHU:
+            from gateway.platforms.feishu import FeishuAdapter, check_feishu_requirements
+            if not check_feishu_requirements():
+                logger.warning("Feishu: lark-oapi not installed or FEISHU_APP_ID/SECRET not set")
+                return None
+            return FeishuAdapter(config)
+
         elif platform == Platform.MATTERMOST:
             from gateway.platforms.mattermost import MattermostAdapter, check_mattermost_requirements
             if not check_mattermost_requirements():
@@ -1500,6 +1509,7 @@ class GatewayRunner:
             Platform.MATTERMOST: "MATTERMOST_ALLOWED_USERS",
             Platform.MATRIX: "MATRIX_ALLOWED_USERS",
             Platform.DINGTALK: "DINGTALK_ALLOWED_USERS",
+            Platform.FEISHU: "FEISHU_ALLOWED_USERS",
         }
         platform_allow_all_map = {
             Platform.TELEGRAM: "TELEGRAM_ALLOW_ALL_USERS",
@@ -1512,6 +1522,7 @@ class GatewayRunner:
             Platform.MATTERMOST: "MATTERMOST_ALLOW_ALL_USERS",
             Platform.MATRIX: "MATRIX_ALLOW_ALL_USERS",
             Platform.DINGTALK: "DINGTALK_ALLOW_ALL_USERS",
+            Platform.FEISHU: "FEISHU_ALLOW_ALL_USERS",
         }
 
         # Per-platform allow-all flag (e.g., DISCORD_ALLOW_ALL_USERS=true)