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(

tests/test_cover.py

@@ -3,13 +3,15 @@ from collections import Counter
 from datetime import date
 from unittest.mock import patch, MagicMock
 from io import BytesIO
-from PIL import Image as PILImage
+from PIL import Image as PILImage, ImageDraw, ImageFont
 
 from src.cover import (
     generate_programmatic_cover,
     generate_ai_cover,
     generate_cover,
     _get_dominant_category,
+    _truncate_to_width,
+    _get_font,
     CATEGORY_PROMPTS,
 )
 
@@ -109,3 +111,28 @@ def test_get_dominant_category():
 def test_category_prompts_include_massachusetts():
     for category, prompt in CATEGORY_PROMPTS.items():
         assert "Massachusetts" in prompt, f"Prompt for {category} missing 'Massachusetts'"
+
+
+def test_truncate_to_width_respects_pixel_budget():
+    font = _get_font(18)
+    short = "Short text"
+    result = _truncate_to_width(short, font, 400)
+    assert result == short, "Short text should not be truncated"
+
+    long = "A" * 200
+    result = _truncate_to_width(long, font, 400)
+    assert result.endswith("\u2026"), "Long text should end with ellipsis"
+    assert len(result) < len(long), "Truncated text should be shorter"
+
+
+def test_truncate_to_width_fits_within_budget():
+    font = _get_font(18)
+    long = "This is a really long headline that should definitely be truncated to fit"
+    max_width = 448
+    result = _truncate_to_width(long, font, max_width)
+
+    dummy = PILImage.new("RGBA", (1, 1))
+    draw = ImageDraw.Draw(dummy)
+    bbox = draw.textbbox((0, 0), result, font=font)
+    rendered_width = bbox[2] - bbox[0]
+    assert rendered_width <= max_width, f"Rendered width {rendered_width} exceeds {max_width}"