feat: 添加信息图插件，并更新相关插件模板和开发文档。

plugins/actions/summary/summary.py

@@ -325,6 +325,10 @@ class Action:
             default=False,
             description="Whether to force clear previous plugin results (if True, overwrites instead of merging).",
         )
+        MESSAGE_COUNT: int = Field(
+            default=1,
+            description="Number of recent messages to use for generation. Set to 1 for just the last message, or higher for more context.",
+        )
 
     def __init__(self):
         self.valves = self.Valves()
@@ -400,6 +404,21 @@ class Action:
         pattern = r"```html\s*<!-- OPENWEBUI_PLUGIN_OUTPUT -->[\s\S]*?```"
         return re.sub(pattern, "", content).strip()
 
+    def _extract_text_content(self, content) -> str:
+        """Extract text from message content, supporting multimodal message formats"""
+        if isinstance(content, str):
+            return content
+        elif isinstance(content, list):
+            # Multimodal message: [{"type": "text", "text": "..."}, {"type": "image_url", ...}]
+            text_parts = []
+            for item in content:
+                if isinstance(item, dict) and item.get("type") == "text":
+                    text_parts.append(item.get("text", ""))
+                elif isinstance(item, str):
+                    text_parts.append(item)
+            return "\n".join(text_parts)
+        return str(content) if content else ""
+
     def _merge_html(
         self,
         existing_html_code: str,
@@ -492,10 +511,32 @@ class Action:
         original_content = ""
         try:
             messages = body.get("messages", [])
-            if not messages or not messages[-1].get("content"):
+            if not messages:
                 raise ValueError("Unable to get valid user message content.")
 
-            original_content = messages[-1]["content"]
+            # Get last N messages based on MESSAGE_COUNT
+            message_count = min(self.valves.MESSAGE_COUNT, len(messages))
+            recent_messages = messages[-message_count:]
+
+            # Aggregate content from selected messages with labels
+            aggregated_parts = []
+            for i, msg in enumerate(recent_messages, 1):
+                text_content = self._extract_text_content(msg.get("content"))
+                if text_content:
+                    role = msg.get("role", "unknown")
+                    role_label = (
+                        "User"
+                        if role == "user"
+                        else "Assistant" if role == "assistant" else role
+                    )
+                    aggregated_parts.append(
+                        f"[{role_label} Message {i}]\n{text_content}"
+                    )
+
+            if not aggregated_parts:
+                raise ValueError("Unable to get valid user message content.")
+
+            original_content = "\n\n---\n\n".join(aggregated_parts)
 
             if len(original_content) < self.valves.MIN_TEXT_LENGTH:
                 short_text_message = f"Text content too short ({len(original_content)} chars), recommended at least {self.valves.MIN_TEXT_LENGTH} chars for effective deep analysis.\n\n💡 Tip: For short texts, consider using '⚡ Flash Card' for quick refinement."