feat: enforce 85% test coverage in CI and fix cross-platform strftime bug

Add pyproject.toml with pytest-cov config so CI fails if coverage drops
below 85%. Fix series_view _format_start using Linux-only %-I/%-d codes
that crash on Windows — use manual formatting instead.

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

app/series_view.py

@@ -165,7 +165,10 @@ def _format_start(start_utc):
         )
     except ValueError:
         return "", ""
-    return dt.strftime("%-I:%M %p ET"), dt.strftime("%a %b %-d")
+    hour = dt.strftime("%I").lstrip("0") or "12"
+    time_str = f"{hour}:{dt.strftime('%M %p')} ET"
+    date_str = f"{dt.strftime('%a %b')} {dt.day}"
+    return time_str, date_str
 
 
 def _to_int(value, default=0):