feat(cover): pixel-width headline truncation and larger font

Replace character-count truncation (45 chars) with Pillow textbbox
pixel-width measurement. Bump headline font 14→18, line spacing 22→26.

Made-with: Cursor

src/cover.py

@@ -70,6 +70,23 @@ def _get_dominant_category(categories: list[str]) -> str:
     return most_common
 
 
+def _truncate_to_width(
+    text: str, font: ImageFont.FreeTypeFont, max_width: int
+) -> str:
+    dummy = PILImage.new("RGBA", (1, 1))
+    draw = ImageDraw.Draw(dummy)
+    bbox = draw.textbbox((0, 0), text, font=font)
+    if (bbox[2] - bbox[0]) <= max_width:
+        return text
+    ellipsis = "\u2026"
+    for i in range(len(text) - 1, 0, -1):
+        candidate = text[:i] + ellipsis
+        bbox = draw.textbbox((0, 0), candidate, font=font)
+        if (bbox[2] - bbox[0]) <= max_width:
+            return candidate
+    return ellipsis
+
+
 def _draw_text_overlays(
     draw: ImageDraw.ImageDraw,
     width: int,
@@ -80,7 +97,7 @@ def _draw_text_overlays(
 ) -> None:
     title_font = _get_font(38)
     date_font = _get_font(20)
-    headline_font = _get_font(14)
+    headline_font = _get_font(18)
 
     draw.rectangle([(0, 0), (width, 90)], fill=(0, 0, 0, 204))
     draw.text(
@@ -100,18 +117,18 @@ def _draw_text_overlays(
 
     if headlines:
         max_headlines = min(len(headlines), 5)
-        strip_height = 28 + max_headlines * 22
+        strip_height = 28 + max_headlines * 26
         strip_top = height - strip_height
         draw.rectangle(
             [(0, strip_top), (width, height)], fill=(0, 0, 0, 170)
         )
+        max_width = width - 32
         y = strip_top + 8
         for headline in headlines[:max_headlines]:
             text = f"\u2022 {headline}"
-            if len(text) > 45:
-                text = text[:42] + "..."
+            text = _truncate_to_width(text, headline_font, max_width)
             draw.text((16, y), text, fill="white", font=headline_font)
-            y += 22
+            y += 26
 
 
 def generate_programmatic_cover(