Fix confidence score: truncate instead of round to prevent 99.95%+ showing as 100%

The previous %.1f formatting rounded 0.9999 → 100.0%. Added a custom Jinja2
filter that uses math.floor to truncate, so 0.9999 → 99.9% and only true 1.0
shows 100.0%.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

app.py

@@ -3,6 +3,7 @@ FastAPI + HTMX app for browsing arxiv papers with new ML datasets.
 Downloads Lance dataset from HuggingFace Hub and loads locally.
 """
 
+import math
 import re
 from datetime import date, timedelta
 from functools import lru_cache
@@ -46,9 +47,18 @@ def highlight_search(text: str, search: str) -> Markup:
     return Markup(highlighted)
 
 
-# Register custom filter
+# Register custom filters
 templates.env.filters["highlight"] = highlight_search
 
+
+def confidence_fmt(score):
+    """Format confidence as percentage, truncating to 1 decimal to avoid rounding 99.95->100."""
+    pct = math.floor(score * 1000) / 10
+    return f"{pct:.1f}"
+
+
+templates.env.filters["confidence"] = confidence_fmt
+
 # Dataset config
 DATASET_REPO = "librarian-bots/arxiv-cs-papers-lance"
 

templates/partials/paper_card.html

@@ -36,7 +36,7 @@
             </span>
         </span>
         <span class="text-gray-400 inline-flex items-center gap-1">
-            {{ "%.1f"|format(paper.confidence_score * 100) }}% conf.
+            {{ paper.confidence_score|confidence }}% conf.
             <span class="cursor-help" title="Model confidence this paper introduces a new dataset">
                 <svg class="w-3.5 h-3.5 text-gray-300" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                     <circle cx="12" cy="12" r="10" stroke-width="1.5"></circle>
@@ -47,7 +47,7 @@
         </span>
         {% else %}
         <span class="{% if paper.confidence_score < 0.8 %}text-gray-400{% else %}text-gray-500{% endif %} inline-flex items-center gap-1">
-            {{ "%.1f"|format(paper.confidence_score * 100) }}% conf.
+            {{ paper.confidence_score|confidence }}% conf.
             <span class="cursor-help" title="Model confidence this paper introduces a new dataset">
                 <svg class="w-3.5 h-3.5 {% if paper.confidence_score < 0.8 %}text-gray-300{% else %}text-gray-400{% endif %}" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                     <circle cx="12" cy="12" r="10" stroke-width="1.5"></circle>