fix: drop InlineTextBox nodes from text snapshots (#3202)

## Problem

In verbose snapshots (`interestingOnly: false`), Puppeteer serializes
`InlineTextBox` children of `StaticText` nodes. These nodes are layout
line fragments. They repeat the parent text and have no `backendNodeId`,
so no tool can target them.

They also all share one uid: the key `${loaderId}_${backendNodeId}`
resolves to `${loaderId}_undefined` for every one of them.

Example from the Wikipedia "Google Chrome" article:

```
uid=2_3 "Jump to content"
  uid=2_2658 InlineTextBox "Jump "
  uid=2_2658 InlineTextBox "to "
  uid=2_2658 InlineTextBox "content"
```

## Fix

`TextSnapshot.assignIds` filters out `InlineTextBox` children when it
builds the tree. This removes them from the text output, the JSON
output, and `idToNode`.

## Results

Wikipedia "Google Chrome" article:

| Mode | Before | After |
|---|---|---|
| Normal | 8,054 lines / 661 KB | 8,054 lines / 661 KB |
| Verbose | 27,676 lines / 2,150 KB | 18,373 lines / 1,429 KB (-34%) |

## Test

Added a real-browser test in `tests/TextSnapshot.test.ts`. The test
depends on Puppeteer's actual serialization. It fails without the fix
and passes with it.

src/TextSnapshot.ts

@@ -14,6 +14,15 @@ import type {DevToolsData} from './tools/ToolDefinition.js';
 import type {TextSnapshotNode} from './types.js';
 import {logger} from './utils/logger.js';
 
+/**
+ * InlineTextBox nodes are layout line fragments of a StaticText node. They
+ * repeat the parent text, have no backendNodeId and cannot be targeted by
+ * tools. Puppeteer only serializes them for non-interesting-only snapshots.
+ */
+function isLayoutOnlyNode(node: SerializedAXNode): boolean {
+  return node.role === 'InlineTextBox';
+}
+
 export class TextSnapshot {
   static nextSnapshotId = 1;
 
@@ -94,7 +103,9 @@ export class TextSnapshot {
         ...node,
         id,
         children: node.children
-          ? node.children.map(child => assignIds(child))
+          ? node.children
+              .filter(child => !isLayoutOnlyNode(child))
+              .map(child => assignIds(child))
           : [],
       };
 

tests/McpResponse.test.js.snapshot

@@ -405,7 +405,6 @@ uid=1_0 RootWebArea "My test page" url="about:blank"
     uid=1_2 ignored
       uid=1_3 complementary
         uid=1_4 "test"
-          InlineTextBox "test"
 
 `;
 
@@ -432,13 +431,7 @@ exports[`McpResponse > returns verbose snapshot and structured content 2`] = `
                   {
                     "id": "1_4",
                     "role": "StaticText",
-                    "name": "test",
-                    "children": [
-                      {
-                        "role": "InlineTextBox",
-                        "name": "test"
-                      }
-                    ]
+                    "name": "test"
                   }
                 ]
               }
@@ -467,7 +460,6 @@ uid=1_0 RootWebArea "My test page" url="about:blank"
     uid=1_2 ignored
       uid=1_3 complementary
         uid=1_4 "test"
-          InlineTextBox "test"
 
 `;
 

tests/TextSnapshot.test.ts

@@ -33,7 +33,7 @@ describe('TextSnapshot', () => {
           loaderId: '1',
           backendNodeId: 2,
           children: [
-            createMockAXNode('InlineTextBox', {
+            createMockAXNode('StaticText', {
               name: 'alpha',
               loaderId: '1',
             }),
@@ -43,7 +43,7 @@ describe('TextSnapshot', () => {
           loaderId: '1',
           backendNodeId: 3,
           children: [
-            createMockAXNode('InlineTextBox', {
+            createMockAXNode('StaticText', {
               name: 'beta',
               loaderId: '1',
             }),
@@ -54,21 +54,21 @@ describe('TextSnapshot', () => {
     page.pptrPage.accessibility.snapshot.resolves(mockRoot);
 
     const snapshot = await TextSnapshot.create(page, {verbose: true});
-    const inlineNodes = [...snapshot.idToNode.values()].filter(
-      node => node.role === 'InlineTextBox',
+    const textNodes = [...snapshot.idToNode.values()].filter(
+      node => node.role === 'StaticText',
     );
 
-    assert.strictEqual(inlineNodes.length, 0);
+    assert.strictEqual(textNodes.length, 0);
 
     const paragraph1 = snapshot.idToNode.get('1_1');
     assert.strictEqual(paragraph1?.role, 'paragraph');
-    assert.strictEqual(paragraph1?.children[0]?.role, 'InlineTextBox');
+    assert.strictEqual(paragraph1?.children[0]?.role, 'StaticText');
     assert.strictEqual(paragraph1?.children[0]?.id, '');
     assert.strictEqual(paragraph1?.children[0]?.name, 'alpha');
 
     const paragraph2 = snapshot.idToNode.get('1_2');
     assert.strictEqual(paragraph2?.role, 'paragraph');
-    assert.strictEqual(paragraph2?.children[0]?.role, 'InlineTextBox');
+    assert.strictEqual(paragraph2?.children[0]?.role, 'StaticText');
     assert.strictEqual(paragraph2?.children[0]?.id, '');
     assert.strictEqual(paragraph2?.children[0]?.name, 'beta');
 
@@ -104,6 +104,28 @@ describe('TextSnapshot', () => {
     });
   });
 
+  it('drops InlineTextBox nodes from verbose snapshots', async () => {
+    await withMcpContext(async (_response, context) => {
+      const page = context.getSelectedMcpPage();
+      await page.pptrPage.setContent(
+        html`<p style="width: 40px">Some wrapped text content</p>`,
+      );
+
+      const snapshot = await TextSnapshot.create(page, {verbose: true});
+
+      let staticTextNode: TextSnapshotNode | undefined;
+      for (const node of snapshot.idToNode.values()) {
+        assert.notStrictEqual(node.role, 'InlineTextBox');
+        if (node.role === 'StaticText') {
+          staticTextNode = node;
+        }
+      }
+      assert.ok(staticTextNode, 'StaticText node should be in the snapshot');
+      assert.strictEqual(staticTextNode.name, 'Some wrapped text content');
+      assert.deepStrictEqual(staticTextNode.children, []);
+    });
+  });
+
   it('inserts extraHandles into the snapshot correctly', async () => {
     await withMcpContext(async (_response, context) => {
       const page = context.getSelectedMcpPage();