fix(markdown): preserve URLs inside inline code spans (#4681)

Inline backtick spans were converted to <code> only at the end of
mdToHtml, after the bare-URL autolink and <a>/allowed-HTML passes. A URL
inside inline code is preceded by a space, so the autolink wrapped it in
an <a> tag and swapped it for an ___ALLOWED_HTML_ placeholder, corrupting
commands like `irm http://127.0.0.1:3000/x`.

Extract inline code into placeholders before the link passes, mirroring
the existing fenced-code-block handling, and restore them last so
placeholders carried inside restored <a> blocks resolve. Escape the code
at extraction time since it now bypasses the global escape pass.

static/js/markdown.js

@@ -483,6 +483,7 @@ export function processWithThinking(text) {
 export function mdToHtml(src, opts) {
   const allowedHtmlBlocks = [];
   const codeBlocks = [];
+  const inlineCodeBlocks = [];
   const mermaidBlocks = [];
   let s = (src ?? '');
 
@@ -521,6 +522,19 @@ export function mdToHtml(src, opts) {
     return placeholder;
   });
 
+  // Extract inline code spans before the link/autolink/HTML passes, mirroring
+  // the fenced-block handling above. A URL inside `inline code` (e.g.
+  // `irm http://127.0.0.1:3000/x`) is preceded by a space, so the bare-URL
+  // autolink matches it, wraps it in an <a> tag, and swaps that for an
+  // ___ALLOWED_HTML_ placeholder — corrupting the command. The old inline-code
+  // pass ran after those passes, too late to protect it.
+  s = s.replace(/`([^`]+?)`/g, (match, code) => {
+    if (code.startsWith('___CODE_BLOCK_') || code.startsWith('___MERMAID_BLOCK_')) return match;
+    const placeholder = `___INLINE_CODE_${inlineCodeBlocks.length}___`;
+    inlineCodeBlocks.push(`<code>${escapeHtml(code)}</code>`);
+    return placeholder;
+  });
+
   // Repair common ways the agent mangles the entity-anchor convention
   // (`[Name](#kind-<id>)`). Models reliably get the single-link case
   // right but slip into other formats when listing many in a table.
@@ -678,12 +692,6 @@ export function mdToHtml(src, opts) {
     return html;
   });
 
-  // Inline code (but not placeholders)
-  s = s.replace(/`([^`]+?)`/g, (match, code) => {
-    if (code.startsWith('___CODE_BLOCK_') || code.startsWith('___ALLOWED_HTML_')) return match;
-    return `<code>${code}</code>`;
-  });
-
   // Horizontal rules (must come before bold/italic to avoid * conflicts)
   s = s.replace(/^(?:---|\*\*\*|___)\s*$/gm, '<hr>');
 
@@ -756,6 +764,14 @@ export function mdToHtml(src, opts) {
     s = s.replace(`___CODE_BLOCK_${index}___`, block);
   });
 
+  // Restore inline code spans last, so placeholders carried inside restored
+  // <a>/allowed-HTML blocks are resolved too. The function replacer keeps the
+  // escaped code literal — e.g. a shell snippet like `echo $1` is not treated
+  // as a regex back-reference.
+  inlineCodeBlocks.forEach((block, index) => {
+    s = s.replace(`___INLINE_CODE_${index}___`, () => block);
+  });
+
   return _useSvgEmoji() ? svgifyEmoji(s, opts) : s;
 }