⌘ + ↵ only sends current line to console in .qmd chunks

Bug description

After updating to Positron 2025.07.0 (build 204) this morning, I can no longer execute multi-line R chunks in .qmd documents with ⌘ + ↵ on macOS.
The issue occurs only when the closing back-ticks of a code chunk (```) are immediately followed by a callout start (:::) with no blank line in between. In that situation, regardless of the cursor position, only the line where the cursor sits is sent to the console, so the code that reaches the console is incomplete or incorrect.

It worked well (with and without the blank line) with my previous Positron version (Positron-2025.04.0-250).
The problem affects manual execution only, the preview rendering is unaffected.

Steps to reproduce

---
title: "Test"
output: html
---

```{r}
library(dplyr)

iris %>%
  group_by(Species) %>% 
  summarise(mean = mean(Sepal.Width))
```

::: {.callout-caution}

```{r}
sessionInfo()
```
:::

However, inserting a blank line between the closing ``` of the code chunk and the closing ::: of the callout restores the expected behaviour.

Your environment

Positron

Positron Version: 2025.07.0 build 204
Code - OSS Version: 1.100.3
Commit: 03ae7a5393c776bb24c23d2aa6a6bfbba90cbc5e
Date: 2025-06-30T16:29:03.492Z
Electron: 34.5.1
Chromium: 132.0.6834.210
Node.js: 20.19.0
V8: 13.2.152.41-electron.0
OS: Darwin arm64 24.5.0

Quarto

quarto -v 1.7.29

Identifier
quarto.quarto
Version
1.123.0
Last Updated
2025-06-18, 09:07:52

Start by reproducing the issue with the provided .qmd document on macOS, focusing on manual ⌘ + ↵ execution when a closing code fence is followed immediately by a callout. Trace the entry point that selects the code sent to the console. Done means the full current chunk executes correctly both with and without the blank line, while preview rendering remains unaffected.