[Bug] TextRun borders applied to individual characters instead of entire run

[ShipIM]

Before you submit this issue, have you checked the following

• Is this really a problem?
• I have searched the Github Issues for similar issues, but did not find anything.

Affected packages and versions

latest

Reproduction link

Import or apply a textStyle containing borders with the following JSON:

"ts": {
    "bd": {
      "t": { "s": 1, "cl": { "rgb": "auto" } },
      "r": { "s": 1, "cl": { "rgb": "auto" } },
      "b": { "s": 1, "cl": { "rgb": "auto" } },
      "l": { "s": 1, "cl": { "rgb": "auto" } }
    }
  }

Expected behavior

The border should surround the entire textRun as a single unit, not each character individually.

Word example:

Actual behavior

Each character inside the textRun is individually bordered, making the styling incorrect and inconsistent with the intended textRun border.

Actual output:

System information

No response