fix(review): store non-finite evidence as null and count pending items

canonical_evidence now follows main's non-finite policy (#303): NaN and
±Infinity are written as null instead of raising, so a NaN-stamped graph
never turns a review item limited. The System Overview reports the review
queue's pending total in needs_review.pending, read in the same snapshot
as the Library counts.

database/library.py

@@ -637,7 +637,8 @@ class LibraryOperations:
         pairs (every pair's positive is eligible). ``images`` counts indexed
         ``generated_images`` rows, not files on disk. An image has no rating
         of its own (it shows its linked prompt's), so ``rated_images`` counts
-        the indexed images whose linked prompt is rated.
+        the indexed images whose linked prompt is rated. ``review_pending`` is
+        the Needs review queue's pending total.
         """
         with self.library_snapshot() as (conn, _epoch, _ceiling):
             row = conn.execute(
@@ -645,13 +646,15 @@ class LibraryOperations:
                 "(SELECT COUNT(*) FROM prompt_pairs WHERE archived=0),"
                 "(SELECT COUNT(*) FROM generated_images),"
                 "(SELECT COUNT(*) FROM generated_images gi JOIN prompts r "
-                "ON r.id=gi.prompt_id WHERE r.rating IS NOT NULL)"
+                "ON r.id=gi.prompt_id WHERE r.rating IS NOT NULL),"
+                "(SELECT COUNT(*) FROM media_review_items WHERE state='pending')"
             ).fetchone()
         return {
             "positive_prompts": row[0],
             "negative_variants": row[1],
             "images": row[2],
             "rated_images": row[3],
+            "review_pending": row[4],
         }
 
     def usage_by_category(self) -> list[dict]:

database/review_schema.py

@@ -38,6 +38,11 @@ from .annotation_schema import TABLES as ANNOTATION_TABLES
 from .annotation_schema import _catalog as _annotation_catalog
 from .annotation_schema import annotation_schema_error
 
+try:
+    from ..utils.json_strict import dumps_strict
+except ImportError:
+    from utils.json_strict import dumps_strict
+
 SCHEMA_VERSION = 1
 METADATA_TABLE = "media_review_metadata"
 ITEMS_TABLE = "media_review_items"
@@ -173,12 +178,21 @@ def canonical_evidence(value: Any) -> str:
     """Serialize one evidence object canonically; ``ValueError`` when invalid.
 
     The text is a JSON object with sorted keys, no whitespace, ASCII only and
-    no NaN/infinity, at most ``MAX_EVIDENCE_BYTES`` bytes.
+    no NaN/infinity, at most ``MAX_EVIDENCE_BYTES`` bytes. A non-finite number
+    (ComfyUI stamps ``NaN`` into graphs) is written as ``null``, the store's
+    policy everywhere (``utils.json_strict.dumps_strict``).
     """
     if not isinstance(value, dict):
         raise ValueError("Review evidence must be a JSON object")
     try:
-        text = _ENCODER.encode(value)
+        try:
+            text = _ENCODER.encode(value)
+        except ValueError as error:
+            if "Out of range float" not in str(error):
+                raise
+            text = dumps_strict(
+                value, sort_keys=True, separators=(",", ":"), ensure_ascii=True
+            )
     except (TypeError, RecursionError) as error:
         raise ValueError(f"Review evidence is not serializable: {error}") from None
     if len(text) > MAX_EVIDENCE_BYTES: