feat(modules): 帮助中心、工单、工作流与多渠道接入

补齐 FAQ、帮助中心、工单、可视化工作流及 Telegram/WhatsApp/Slack 等渠道模块。

backend/app/channels/sms/adapter.py

@@ -0,0 +1,60 @@
+"""
+Copyright 2024-2026 ChatterMate
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+"""
+
+from typing import ClassVar, List, Optional
+
+from app.channels.base import ChannelAdapter, InboundMessage, SendResult
+from app.channels.registry import register_adapter
+from app.channels.sms.base import MAX_MESSAGE_LENGTH, get_provider
+from app.models.channels import ChannelAccount, ChannelConversation, ChannelType
+from app.core.logger import get_logger
+
+logger = get_logger(__name__)
+
+
+def account_provider_name(account: ChannelAccount) -> str:
+    """The SMS provider chosen for this account (stored non-secret in settings;
+    defaults to twilio for accounts connected before providers existed)."""
+    return (account.settings or {}).get("provider", "twilio")
+
+
+class SmsAdapter(ChannelAdapter):
+    """The 'sms' channel. Inbound parsing/verification is provider-specific and
+    handled by the /webhooks/sms route; this adapter only dispatches outbound
+    sends to the account's provider."""
+
+    channel_type: ClassVar[str] = ChannelType.SMS.value
+
+    async def verify_webhook(self, headers: dict, raw_body: bytes, account: Optional[ChannelAccount]) -> bool:
+        # SMS inbound is verified per-provider inside the webhook route.
+        return account is not None
+
+    def parse_inbound(self, payload: dict) -> List[InboundMessage]:
+        # Inbound is parsed per-provider in the webhook route, not here.
+        return []
+
+    async def send_text(self, account: ChannelAccount, conversation: ChannelConversation, text: str) -> SendResult:
+        provider = get_provider(account_provider_name(account))
+        if provider is None:
+            return SendResult(ok=False, error=f"Unknown SMS provider '{account_provider_name(account)}'")
+        return await provider.send(account, conversation.external_conversation_id, text)
+
+    def format_outbound(self, markdown: str) -> str:
+        plain = markdown.replace("**", "").replace("__", "")
+        return plain[:MAX_MESSAGE_LENGTH]
+
+
+register_adapter(SmsAdapter())