Scale chart width with the number of visible weeks

Stretching 5 weeks across the same 960-wide canvas as 26 weeks left
huge empty gaps. Compute the SVG width from the bucket count
(`width = clamp(560, left + right + 40 * weeks, 960)`) and drop the
README `width="960"` override so the chart renders at its natural
size — a 5-week chart now occupies the 560 minimum, a long history
grows toward the 960 ceiling without ever overflowing.

Co-authored-by: Open Codex <hff582580@gmail.com>

Author: LEON-gittech

.github/npm-total-downloads.svg

@@ -189,10 +189,18 @@ def svg_text(x, y, text, extra=""):
 
 
 def generate_svg(package_name, cumulative_rows):
-    width = 960
-    height = 300
+    # Scale width with bucket count so a 5-week chart isn't stretched across
+    # the same canvas as a 26-week one. Clamp to a min so the header text
+    # never wraps, and to the historical max (960) so long histories don't
+    # blow past the README column width.
+    per_bucket = 40
+    min_width = 560
+    max_width = 960
     left = 70
     right = 32
+    bucket_count = max(1, len(cumulative_rows))
+    width = max(min_width, min(max_width, left + right + per_bucket * bucket_count))
+    height = 300
     top = 58
     bottom = 56
     chart_w = width - left - right

.github/scripts/update_npm_download_chart.py

@@ -18,7 +18,7 @@
 </p>
 
 <p align="center">
-  <a href="https://www.npmjs.com/package/@leonw24/open-codex"><img src="https://raw.githubusercontent.com/LEON-gittech/Open-Codex-CLI/main/.github/npm-total-downloads.svg" alt="Open Codex CLI cumulative npm downloads chart" width="960" /></a>
+  <a href="https://www.npmjs.com/package/@leonw24/open-codex"><img src="https://raw.githubusercontent.com/LEON-gittech/Open-Codex-CLI/main/.github/npm-total-downloads.svg" alt="Open Codex CLI cumulative npm downloads chart" /></a>
 </p>
 
 <p align="center">