fix(status): banner Details strips Markdown syntax, not every #, _, >, * (#308)

plain() deleted those characters everywhere, so "join #lotus-general"
lost its #, snake_case and @some_user lost underscores, "->" became
"-", "5 * 3" became "5  3", and "<b>" became "<b". Strip only syntax:
heading / quote / list markers at line start, paired **x** *x* _x_ `x`,
and HTML tags.

Fixes #308

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017PCb59uY3UKqDqt7B6hzd5

src/app/utils/kumaStatus.test.ts

@@ -1,6 +1,7 @@
 import { test } from 'node:test';
 import assert from 'node:assert/strict';
 import {
+  plain,
   DEFAULT_GROUPS,
   kumaBeatTime,
   kumaUrls,
@@ -260,3 +261,27 @@ test('a dismissed calls-down banner lets the next one through, never hides serve
     'server-down',
   );
 });
+
+test('plain: strips Markdown syntax only, keeps ordinary #, _, > and * (#308)', () => {
+  assert.equal(
+    plain('join #lotus-general or #announcements:lotusguild.org'),
+    'join #lotus-general or #announcements:lotusguild.org',
+  );
+  assert.equal(
+    plain('ping @some_user about snake_case and C#'),
+    'ping @some_user about snake_case and C#',
+  );
+  assert.equal(
+    plain('calls -> fixed, > 5 people, 5 * 3 = 15'),
+    'calls -> fixed, > 5 people, 5 * 3 = 15',
+  );
+  assert.equal(
+    plain('# Heading\n* item one\n- item two\n> quoted'),
+    'Heading\nitem one\nitem two\nquoted',
+  );
+  assert.equal(plain('**bold**, *em*, _em_, `/sfu/get`'), 'bold, em, em, /sfu/get');
+  assert.equal(
+    plain('Read the <b>guide</b> <img src=x onerror=alert(1)> [docs](https://x.y)'),
+    'Read the guide  docs',
+  );
+});

src/app/utils/kumaStatus.ts

@@ -240,12 +240,25 @@ const incidentTone = (style: string): BannerTone => {
 };
 
 /** Markdown-ish incident text as plain text for the Details line. */
-const plain = (s: string): string =>
+/**
+ * [Gitea #308] Markdown → plain text for the Details line. Strips only the
+ * syntax: removing every `*_\`#>` also broke "#lotus-general", "snake_case",
+ * "->" and "5 * 3". HTML tags are dropped (React escapes the text anyway).
+ */
+export const plain = (s: string): string =>
   s
     .replace(/!\[[^\]]*\]\([^)]*\)/g, '')
     .replace(/\[([^\]]+)\]\([^)]*\)/g, '$1')
-    .replace(/[*_`#>]/g, '')
+    .replace(/<\/?[a-z][^>]*>/gi, '')
-    .replace(/\s+\n/g, '\n')
+    .replace(/^[ \t]{0,3}#{1,6}[ \t]+/gm, '')
+    .replace(/^[ \t]*>[ \t]?/gm, '')
+    .replace(/^[ \t]*[*+-][ \t]+/gm, '')
+    .replace(/`([^`\n]+)`/g, '$1')
+    .replace(/\*\*(?=\S)([^*\n]*?\S)\*\*/g, '$1')
+    .replace(/__(?=\S)([^_\n]*?\S)__/g, '$1')
+    .replace(/(^|[^\w*])\*(?=\S)([^*\n]*?\S)\*(?![\w*])/g, '$1$2')
+    .replace(/(^|[^\w])_(?=\S)([^_\n]*?\S)_(?!\w)/g, '$1$2')
+    .replace(/[ \t]+\n/g, '\n')
     .trim();
 
 /**