make usernames linkable in news (#3200)

## Description:

make usernames linkable in news

now:
<img width="399" height="153" alt="image"
src="https://github.com/user-attachments/assets/39644fe2-9af1-4765-b839-9f8b5f9d0418"
/>


before:
<img width="409" height="82" alt="image"
src="https://github.com/user-attachments/assets/d7a1c37e-63cf-4417-ac61-c6db39a33851"
/>



## Please complete the following:

- [x] I have added screenshots for all UI updates
- [x] I process any text displayed to the user through translateText()
and I've added it to the en.json file
- [x] I have added relevant tests to the test directory
- [x] I confirm I have thoroughly tested these changes and take full
responsibility for any bugs introduced

## Please put your Discord username so you can be contacted if a bug or
regression is found:

w.o.n

Co-authored-by: iamlewis <lewismmmm@gmail.com>

src/client/NewsMarkdown.ts

@@ -0,0 +1,30 @@
+const GITHUB_PR_URL_REGEX =
+  /(?<!\()\bhttps:\/\/github\.com\/openfrontio\/OpenFrontIO\/pull\/(\d+)\b/g;
+const GITHUB_COMPARE_URL_REGEX =
+  /(?<!\()\bhttps:\/\/github\.com\/openfrontio\/OpenFrontIO\/compare\/([\w.-]+)\b/g;
+const GITHUB_MENTION_REGEX =
+  /(^|[^\w/[`])@([a-z\d](?:[a-z\d-]{0,37}[a-z\d])?)(?![\w-])/gim;
+
+export function normalizeNewsMarkdown(markdown: string): string {
+  return (
+    markdown
+      // Convert bold header lines (e.g. "**Title**") into real Markdown headers.
+      // Exclude lines starting with - or * to avoid converting bullet points.
+      .replace(/^([^\-*\s].*?) \*\*(.+?)\*\*$/gm, "## $1 $2")
+      .replace(
+        GITHUB_PR_URL_REGEX,
+        (_match, prNumber) =>
+          `[#${prNumber}](https://github.com/openfrontio/OpenFrontIO/pull/${prNumber})`,
+      )
+      .replace(
+        GITHUB_COMPARE_URL_REGEX,
+        (_match, comparison) =>
+          `[${comparison}](https://github.com/openfrontio/OpenFrontIO/compare/${comparison})`,
+      )
+      .replace(
+        GITHUB_MENTION_REGEX,
+        (_match, prefix, username) =>
+          `${prefix}[@${username}](https://github.com/${username})`,
+      )
+  );
+}