feat: clickable zoom reset, Pan tool (H), and batch command support

- Clicking the zoom percentage in the menu bar resets zoom to 100%
- New Pan tool (H key) for explicit left-click-drag panning mode
- Batch command support: agents can send multiple operations in a
  single WebSocket message via {"type": "Batch", "requests": [...]}
  with sequential execution and collected results
- New MCP tool 'batch' accepts a JSON array of request objects
- Nested batches rejected with clear error message
- Updated AGENTS.md with .app rebuild requirement

crates/agcanvas-mcp/src/tools.rs

@@ -187,6 +187,12 @@ pub struct BooleanOpParam {
     pub stroke_width: Option<f32>,
 }
 
+#[derive(Debug, serde::Deserialize, schemars::JsonSchema)]
+pub struct BatchParam {
+    #[schemars(description = "JSON array of request objects. Each object must have a 'type' field and the same parameters as individual tool calls. Example: [{\"type\": \"CreateDrawingElement\", \"shape_type\": \"rectangle\", \"x\": 0, \"y\": 0, \"width\": 100, \"height\": 100}, {\"type\": \"CreateDrawingElement\", \"shape_type\": \"ellipse\", \"center_x\": 200, \"center_y\": 200, \"radius_x\": 50, \"radius_y\": 50}]")]
+    pub requests_json: String,
+}
+
 #[derive(Debug, Clone)]
 pub struct AgCanvasServer {
     ws_url: String,
@@ -521,6 +527,35 @@ impl AgCanvasServer {
         self.call_agcanvas(&request).await
     }
 
+    #[tool(
+        description = "Send multiple Augmented Canvas operations in one request. Accepts a JSON array of request objects and returns one response per operation in a BatchResult."
+    )]
+    async fn batch(
+        &self,
+        Parameters(params): Parameters<BatchParam>,
+    ) -> Result<CallToolResult, McpError> {
+        let requests = match serde_json::from_str::<serde_json::Value>(&params.requests_json) {
+            Ok(serde_json::Value::Array(requests)) => requests,
+            Ok(_) => {
+                return Ok(CallToolResult::error(vec![Content::text(
+                    "Invalid requests_json: expected a JSON array of request objects",
+                )]))
+            }
+            Err(e) => {
+                return Ok(CallToolResult::error(vec![Content::text(format!(
+                    "Invalid requests_json: {}",
+                    e
+                ))]))
+            }
+        };
+
+        let request = serde_json::json!({
+            "type": "Batch",
+            "requests": requests,
+        });
+        self.call_agcanvas(&request).await
+    }
+
     #[tool(description = "Delete a drawing element by its ID.")]
     async fn delete_drawing_element(
         &self,