fix(wiki): protect inline-code spans from cross-ref injection

_inject_cross_refs temporarily replaces backtick spans with null-byte
placeholders before injecting [[slug]] cross-refs, then restores them.
This prevents concept titles inside `code` from being rewritten.
Add tests for inline-code protection and full-list cross-ref injection.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

codex/wiki.py

@@ -284,6 +284,9 @@ def _run_grounding_guard(
 # ---------------------------------------------------------------------------
 
 
+_INLINE_CODE_RE = re.compile(r"`[^`]+`")
+
+
 def _inject_cross_refs(
     markdown: str,
     all_concepts: list[Concept],
@@ -292,8 +295,21 @@ def _inject_cross_refs(
     """Replace occurrences of other concept titles/aliases with ``[[slug]]`` links.
 
     Only exact case-insensitive whole-word matches outside of existing
-    ``[[…]]`` blocks or inline code are replaced.
+    ``[[…]]`` blocks or inline code spans are replaced.
+    Inline-code spans (`` `…` ``) are temporarily protected by null-byte
+    placeholders and restored after injection.
     """
+    # Step 1: protect inline-code spans from replacement
+    placeholders: dict[str, str] = {}
+
+    def _protect(m: re.Match[str]) -> str:
+        key = f"\x00{len(placeholders)}\x00"
+        placeholders[key] = m.group(0)
+        return key
+
+    markdown = _INLINE_CODE_RE.sub(_protect, markdown)
+
+    # Step 2: inject cross-refs on unprotected text
     for concept in all_concepts:
         if concept.slug == current_slug:
             continue
@@ -304,6 +320,11 @@ def _inject_cross_refs(
             pattern = re.compile(rf"(?<!\[\[)\b{escaped}\b(?!\]\])", re.IGNORECASE)
             replacement = f"[[{concept.slug}]]"
             markdown = pattern.sub(replacement, markdown)
+
+    # Step 3: restore inline-code spans
+    for key, val in placeholders.items():
+        markdown = markdown.replace(key, val)
+
     return markdown