feat(dingtalk): implement human input card support and card action handling

- Add a new module `card_callback.py` to handle card action button clicks from DingTalk.
- Introduce `DingTalkCardActionHandler` to process card action callbacks and extract parameters.
- Update `DingTalkAdapter` to manage card state and handle form input through a single card template.
- Add configuration for `human_input_card_template_id` in `dingtalk.yaml` to specify the template for human input.
- Create a new card template `dingtalk_human_input_card.json` for rendering human input prompts and buttons.

src/langbot/libs/dingtalk_api/card_callback.py

@@ -0,0 +1,96 @@
+"""STREAM-mode handler for DingTalk card action button clicks.
+
+DingTalk delivers card-action callbacks over the same WebSocket stream used
+for chatbot messages, under the topic `/v1.0/card/instances/callback`. This
+module subclasses `dingtalk_stream.CallbackHandler` and forwards the parsed
+payload to a coroutine the adapter registers, so the resume-paused-workflow
+logic stays in the platform adapter where it belongs.
+
+The `CardCallbackMessage` returned by `from_dict` exposes:
+
+* `card_instance_id` (from `outTrackId`) — the card whose button was clicked
+* `user_id`  — the clicker's userId
+* `content`  — parsed JSON; the click params live here. Where exactly inside
+               `content` they sit depends on the template binding. We probe
+               the common paths.
+* `extension` — parsed JSON; any extra data we set when delivering the card.
+"""
+
+from __future__ import annotations
+
+from typing import Awaitable, Callable, Optional
+
+import dingtalk_stream  # type: ignore
+from dingtalk_stream import AckMessage
+from dingtalk_stream.card_callback import CardCallbackMessage
+
+
+_PARAM_PATHS = (
+    ('params',),
+    ('cardPrivateData', 'params'),
+    ('userPrivateData', 'params'),
+)
+
+
+def _extract_params(content: dict) -> dict:
+    """Return the action params dict regardless of where the template put it."""
+    for path in _PARAM_PATHS:
+        node = content
+        for key in path:
+            if not isinstance(node, dict):
+                node = None
+                break
+            node = node.get(key)
+            if node is None:
+                break
+        if isinstance(node, dict) and node:
+            return node
+    return {}
+
+
+class DingTalkCardActionHandler(dingtalk_stream.CallbackHandler):
+    def __init__(
+        self,
+        dingtalk_stream_client,
+        on_action: Optional[Callable[[dict], Awaitable[None]]] = None,
+    ):
+        super().__init__()
+        self.dingtalk_client = dingtalk_stream_client
+        self.on_action = on_action
+
+    async def process(self, callback: dingtalk_stream.CallbackMessage):
+        try:
+            message = CardCallbackMessage.from_dict(callback.data)
+            params = _extract_params(message.content if isinstance(message.content, dict) else {})
+
+            # `CardCallbackMessage.from_dict` does not surface `actionId` (the
+            # top-level field that ButtonGroup's sendCardRequest event puts
+            # there). Pull it from the raw callback.data instead.
+            raw = callback.data if isinstance(callback.data, dict) else {}
+            action_id = raw.get('actionId') or ''
+            if not action_id:
+                # Some templates nest it under actionData / cardPrivateData.
+                action_data = raw.get('actionData') or {}
+                if isinstance(action_data, dict):
+                    action_id = action_data.get('actionId') or action_id
+                    if not action_id:
+                        cpd = action_data.get('cardPrivateData') or {}
+                        if isinstance(cpd, dict):
+                            ids = cpd.get('actionIds')
+                            if isinstance(ids, list) and ids:
+                                action_id = str(ids[0])
+
+            payload = {
+                'out_track_id': message.card_instance_id,
+                'user_id': message.user_id,
+                'corp_id': message.corp_id,
+                'action_id': action_id,
+                'params': params,
+                'raw_content': message.content,
+                'extension': message.extension if isinstance(message.extension, dict) else {},
+            }
+            if self.on_action is not None:
+                await self.on_action(payload)
+        except Exception as e:
+            self.logger.error(f'DingTalkCardActionHandler.process error: {e}')
+        return AckMessage.STATUS_OK, 'OK'