Add inverted-axis and aspect-ratio sins; rename slugs

Writes two sins off the backlog. The inverted y-axis is the egregious
one: the fill hangs from the top and the line descends while the values
climb, with every element individually defensible. Aspect ratio is the
quiet one: same twelve numbers, same y-range, only the shape of the box
changes.

Adds Cleveland, McGill & McGill 1988 to the canon — banking to 45 comes
from the shape-parameter paper, not the 1984 ranking already cited, so
citing the latter for it would have misattributed the claim.

Also renames sin slugs to match their retitled pages, and rewrites the
summaries that had started echoing those titles.

Gives line-chart points their mark color explicitly; "point": true was
falling back to Vega's default blue on a red or green line.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01ULE5RRxdQE1ebwefEd2eCM

src/content/sins/too-many-pie-slices.md

@@ -0,0 +1,41 @@
+---
+title: "Too Many Slices in a Pie Chart"
+summary: "Near-identical wedges nobody can rank by eye, when a sorted bar chart would have answered instantly."
+poke: "More slices than anyone can rank by eye. A bar chart was right there."
+category: "Chart-Type Abuse"
+severity: 3
+tags: ["pie chart", "part-to-whole", "comparison"]
+badChart: "pie-overload-bad"
+fixedChart: "pie-overload-fixed"
+date: 2026-08-05
+citations:
+  - key: fewpies
+    note: "“Save the Pies for Dessert” — the definitive, free takedown of the overloaded pie."
+  - key: clevelandmcgill
+    note: "Their ranking shows angle and area are judged far worse than position along a scale."
+  - key: junkcharts
+    note: "Kaiser Fung’s running #onelesspie campaign exists for precisely this chart."
+  - key: datatoviz
+    note: "Pie charts are the first entry in its catalogue of caveats."
+---
+
+## The sin
+
+The pie chart asks the reader to compare **angles** — something people are
+genuinely bad at. One or two slices, fine. But eight slices, several of them
+within a percentage point of each other? Nobody can tell whether Firefox beats
+Samsung by eyeballing two thin wedges on opposite sides of the circle.
+
+## Why it deceives
+
+Angle and area are hard to judge precisely, and slices scattered around the
+circle can't be lined up against a common baseline. The small categories blur
+into an indistinguishable fringe, and the ranking — usually the whole point —
+becomes guesswork.
+
+## The repentance
+
+Use a **sorted horizontal bar chart**. Every value shares one baseline, the
+ordering is explicit, and long labels sit comfortably beside their bars. Reserve
+the pie for the rare case of two or three parts of an obvious whole — and even
+then, a bar chart rarely does worse.