fix(wiki): basic conflict detection in CompileReport

Add _detect_conflicts() using adversative keyword heuristic (but,
however, in contrast, …) between chunks of different bibkeys; results
populate CompileReport.conflicts and appear in wiki/log.md.
Also add CompileReport.quarantined field (used by Fix 2).

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

codex/config.py

@@ -123,6 +123,17 @@ class Settings(BaseSettings):
         ),
     )
 
+    wiki_min_grounding_rate: float = Field(
+        default=0.5,
+        ge=0.0,
+        le=1.0,
+        description=(
+            "Minimum fraction of claims that must be grounded for a page to be written "
+            "to wiki/<slug>.md. Pages below this threshold are quarantined to "
+            "wiki/draft/<slug>.md instead."
+        ),
+    )
+
     # ------------------------------------------------------------------
     # F-09 Rich Parsing
     # ------------------------------------------------------------------