feat(browser): implement input blocker overlay during automation (#21132)

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>
Co-authored-by: Gaurav <39389231+gsquared94@users.noreply.github.com>
Co-authored-by: Gaurav Ghosh <gaghosh@google.com>

packages/core/src/config/config.ts

@@ -316,6 +316,8 @@ export interface BrowserAgentCustomConfig {
   profilePath?: string;
   /** Model override for the visual agent. */
   visualModel?: string;
+  /** Disable user input on the browser window during automation. Default: true in non-headless mode */
+  disableUserInput?: boolean;
 }
 
 /**
@@ -2888,10 +2890,23 @@ export class Config implements McpContext, AgentLoopContext {
         headless: customConfig.headless ?? false,
         profilePath: customConfig.profilePath,
         visualModel: customConfig.visualModel,
+        disableUserInput: customConfig.disableUserInput,
       },
     };
   }
 
+  /**
+   * Determines if user input should be disabled during browser automation.
+   * Based on the `disableUserInput` setting and `headless` mode.
+   */
+  shouldDisableBrowserUserInput(): boolean {
+    const browserConfig = this.getBrowserAgentConfig();
+    return (
+      browserConfig.customConfig?.disableUserInput !== false &&
+      !browserConfig.customConfig?.headless
+    );
+  }
+
   async createToolRegistry(): Promise<ToolRegistry> {
     const registry = new ToolRegistry(this, this.messageBus);