feat(02-02): implement FeishuResponseFormatter class

- format_success() creates card with green theme
- format_error() creates card with red theme
- format_info() creates card with blue theme
- format_paginated() adds [N/M] marker
- _build_card() creates three-zone structure (header/elements/actions)
- _build_actions() creates interactive button elements

All 6 tests pass. Card JSON uses schema 2.0 with lark_md content.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

gsd-openclaw/src/gsd_openclaw/response_formatter.py

@@ -23,3 +23,61 @@ class CardButton:
     text: str
     value: Dict[str, Any]
     button_type: str = "primary"  # primary, default, danger
+
+
+class FeishuResponseFormatter:
+    """Format responses as Feishu Card messages."""
+
+    def format_success(self, title: str, content: str,
+                       buttons: Optional[List[CardButton]] = None) -> dict:
+        """Format a success response card with green theme."""
+        return self._build_card(title, content, CardTheme.SUCCESS, buttons)
+
+    def format_error(self, title: str, content: str,
+                     buttons: Optional[List[CardButton]] = None) -> dict:
+        """Format an error response card with red theme."""
+        return self._build_card(title, content, CardTheme.ERROR, buttons)
+
+    def format_info(self, title: str, content: str,
+                    buttons: Optional[List[CardButton]] = None) -> dict:
+        """Format an info response card with blue theme."""
+        return self._build_card(title, content, CardTheme.INFO, buttons)
+
+    def format_paginated(self, title: str, content: str,
+                         page: int, total_pages: int) -> dict:
+        """Format a paginated response with [page/total] marker."""
+        footer = f"\n\n---\n[{page}/{total_pages}]"
+        return self._build_card(title, content + footer, CardTheme.INFO)
+
+    def _build_card(self, title: str, content: str, theme: CardTheme,
+                    buttons: Optional[List[CardButton]] = None) -> dict:
+        """Build complete card JSON structure."""
+        card = {
+            "schema": "2.0",
+            "config": {"wide_screen_mode": True},
+            "header": {
+                "title": {"tag": "plain_text", "content": title},
+                "template": theme.value
+            },
+            "elements": [
+                {"tag": "div", "text": {"tag": "lark_md", "content": content}}
+            ]
+        }
+        if buttons:
+            card["elements"].append(self._build_actions(buttons))
+        return card
+
+    def _build_actions(self, buttons: List[CardButton]) -> dict:
+        """Build actions element from button list."""
+        return {
+            "tag": "action",
+            "actions": [
+                {
+                    "tag": "button",
+                    "text": {"tag": "plain_text", "content": btn.text},
+                    "type": btn.button_type,
+                    "value": btn.value
+                }
+                for btn in buttons
+            ]
+        }