fix: use CDP selectAll command for cross-platform field clearing

clearField() used Control+A to select all text before deleting, but on
macOS Chrome, Ctrl+A is the Emacs "beginning of paragraph" binding — not
select-all. This meant the clear tool never actually cleared field content.

Use CDP's `commands: ['selectAll']` parameter on dispatchKeyEvent to trigger
the browser's editing command directly, bypassing platform-specific keyboard
shortcut mappings. Also adds a dedicated Browser.clear() method so the clear
tool no longer routes through fill() with an empty string.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

packages/browseros-agent/apps/server/src/browser/browser.ts

@@ -821,6 +821,22 @@ export class Browser {
     return coords
   }
 
+  async clear(page: number, element: number): Promise<void> {
+    const session = await this.resolveSession(page)
+    await elements.scrollIntoView(session, element)
+    try {
+      await elements.focusElement(session, element)
+    } catch {
+      try {
+        const { x, y } = await elements.getElementCenter(session, element)
+        await mouse.dispatchClick(session, x, y, 'left', 1, 0)
+      } catch {
+        logger.warn('Could not focus element for clear')
+      }
+    }
+    await keyboard.clearField(session)
+  }
+
   async pressKey(page: number, key: string): Promise<void> {
     const session = await this.resolveSession(page)
     await keyboard.pressCombo(session, key)

packages/browseros-agent/apps/server/src/browser/keyboard.ts

@@ -180,31 +180,31 @@ export async function typeText(
 }
 
 export async function clearField(session: ProtocolApi): Promise<void> {
+  // Use the CDP `commands` parameter to trigger the selectAll editing command
+  // directly, bypassing platform-specific keyboard shortcut mappings
+  // (Ctrl+A doesn't select all on macOS Chrome — it's the Emacs "beginning of paragraph" binding)
   await session.Input.dispatchKeyEvent({
-    type: 'keyDown',
+    type: 'rawKeyDown',
     key: 'a',
     code: 'KeyA',
-    modifiers: 2,
-    windowsVirtualKeyCode: 65,
+    commands: ['selectAll'],
   })
   await session.Input.dispatchKeyEvent({
     type: 'keyUp',
     key: 'a',
     code: 'KeyA',
-    modifiers: 2,
-    windowsVirtualKeyCode: 65,
   })
   await session.Input.dispatchKeyEvent({
-    type: 'keyDown',
-    key: 'Delete',
-    code: 'Delete',
-    windowsVirtualKeyCode: 46,
+    type: 'rawKeyDown',
+    key: 'Backspace',
+    code: 'Backspace',
+    windowsVirtualKeyCode: 8,
   })
   await session.Input.dispatchKeyEvent({
     type: 'keyUp',
-    key: 'Delete',
-    code: 'Delete',
-    windowsVirtualKeyCode: 46,
+    key: 'Backspace',
+    code: 'Backspace',
+    windowsVirtualKeyCode: 8,
   })
 }
 

packages/browseros-agent/apps/server/src/tools/input.ts

@@ -177,7 +177,7 @@ export const clear = defineTool({
     element: z.number(),
   }),
   handler: async (args, ctx, response) => {
-    await ctx.browser.fill(args.page, args.element, '', true)
+    await ctx.browser.clear(args.page, args.element)
     response.text(`Cleared [${args.element}]`)
     response.data({ action: 'clear', page: args.page, element: args.element })
     response.includeSnapshot(args.page)