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
 
 

tests/wiki/test_compile.py

@@ -212,6 +212,38 @@ def test_inject_cross_refs_replaces_alias() -> None:
     assert "[[circle-packing]]" in result
 
 
+def test_inject_cross_refs_skips_inline_code() -> None:
+    """Concept titles inside backtick inline-code spans are NOT replaced."""
+    concepts = [
+        Concept(
+            slug="circle-packing",
+            title="circle-packing",
+            aliases=[],
+        ),
+        FIXTURE_CONCEPT,
+    ]
+    # The term "circle-packing" appears both bare (should be replaced)
+    # and inside backticks (should NOT be replaced).
+    text = "Use `circle-packing` for this. See also circle-packing theory."
+    result = _inject_cross_refs(text, concepts, current_slug="lobachevsky-function")
+    assert "`circle-packing`" in result  # inline-code preserved
+    assert "[[circle-packing]]" in result  # bare occurrence replaced
+
+
+def test_inject_cross_refs_full_list_even_when_single_concept() -> None:
+    """Cross-ref injection uses the full concept list, not just the compiled concept."""
+    concepts = [
+        Concept(slug="circle-packing", title="Circle Packing", aliases=[]),
+        Concept(slug="discrete-conformal-map", title="Discrete Conformal Map", aliases=[]),
+        FIXTURE_CONCEPT,
+    ]
+    # Compiling lobachevsky-function only; text mentions the other two concepts
+    text = "Discrete Conformal Map is used with Circle Packing."
+    result = _inject_cross_refs(text, concepts, current_slug="lobachevsky-function")
+    assert "[[circle-packing]]" in result
+    assert "[[discrete-conformal-map]]" in result
+
+
 # ---------------------------------------------------------------------------
 # compile_concept (full mock)
 # ---------------------------------------------------------------------------