Fix multiline EJS syntax highlighting

[Copilot]

Multiline EJS blocks break syntax highlighting for all subsequent HTML content after the closing %>.

<%
for (let i = 0; i < arr.length; i++) {
    const val = arr[i];
%>
    <%= val %>  <!-- This and everything after was broken -->
<% } %>
</li>

Changes

• Unified EJS pattern: Merged tag-ejs-single-line and tag-ejs-multi-line into a single tag-ejs pattern
• Simplified regex: Removed complex lookahead that required closing tag on same line as begin pattern
• Standard scope names: Updated to punctuation.section.embedded.begin/end.ejs

The previous approach had two overlapping patterns with a complex single-line regex that attempted to capture content AND verify the closing tag position in the begin pattern—similar to how the working Atom EJS grammar handles it with simple begin/end pairs.

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Multiline ejs messes up syntax highlighting</issue_title>
<issue_description>```ejs

<% for (let i = 0; i < arr.length; i++) { const val = arr[i]; %> <%= val %> <% } %>

```

Everything after the first closing tag %> has messed up syntax highlighting</issue_description>

Comments on the Issue (you are @copilot in this section)

@ Anyone come up with any solution to this? My goal is just to be able to have multiple lines between EJS tags, for instance: ``` <% entries.forEach(p => { var x = p.number + 1; … %> ``` As shown in my screenshot below, this currently breaks syntax highlighting (notice the closing `` and `` tags are black, and the JS in the `<script>` tag is also affected).

Atom’s EJS extension language-ejs does not have this problem. I started down the rabbit hole of how to make/edit these extensions in hopes of fixing it, but it’s quite a deep hole…

FWIW, here is the .tmLanguage file the Atom extension was converted from:
GitHub > GregoryM > EJS TM > JS Template Syntax

@Betanu701 I don't use ejs much anymore. But if you/or someone does provide a pull request, I would be happy to pull it in!

• Fixes Multiline ejs messes up syntax highlighting #61

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