Reframe the reference list; cite far more widely

"Canon" was leaking onto the public site — a nav item, a footer block, a
page title, a set of CSS class names. It was also driving content
decisions it had no business driving: the backlog was ordered around
which references were still unused, which is curation dressed up as
planning.

The page is now /references/, the list is documented as a bibliography
to grow rather than a canon to curate, and the backlog says plainly that
a sin earns a slot by being worth a page — sources are found to support
it, never the reverse.

Adds six sources (Cairo's Truthful Art, Few's Show Me the Numbers, the
Economist's audit of its own charts, Kosara's eagereyes, WTF
Visualizations, Datawrapper's dual-axis piece) and roughly doubles the
citations on the five published sins, to 5-7 each. Two of the new notes
point at sources that complicate our own position rather than back it.

The Economist essay ships without a URL rather than a guessed one.

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

CLAUDE.md

@@ -31,14 +31,25 @@ Each sin page follows one shape: **poke → proof → why → the fix → receip
   (e.g. the dual-axis "sin" deliberately breaks the one-axis rule; its fix uses
   separate honest panels.) When picking chart colors or building a new chart,
   run the `dataviz` skill and validate the palette with its validator.
-- **Citations are core.** Every sin cites the canon (`src/lib/references.ts`)
-  under "Don't take our word for it." Don't invent authority — point at it.
+- **Citations are core, and generous.** Every sin cites sources
+  (`src/lib/references.ts`) under "Don't take our word for it." Don't invent
+  authority — point at it, and point at as much of it as you honestly can.
+  Five-ish sources per sin is normal; a reader who distrusts one author should
+  find another in the list they don't. Adding a new reference is routine, not an
+  editorial event — the file is a bibliography to grow, **not a canon to
+  curate**, and coverage of it is not a goal in itself.
+  Never stretch a source to fit: if it doesn't actually make the claim, cite one
+  that does or leave it out. Getting an attribution wrong costs more than a
+  thinner page. A source that *complicates* our position (Kosara on pie charts,
+  Datawrapper's second thoughts on dual axes) is worth citing too — say so in
+  the note.
 - **Internal build decisions stay out of visitor-facing content and the DOM.**
   The design system (Carbon), the typeface (IBM Plex), and the inspiration
   (nohello.net) are engineering choices — they must not appear in page copy,
   the footer, meta tags, or CSS class names on the public site. (They were
   scrubbed once already; keep them out.) Naming them *here*, in repo docs, is
-  fine.
+  fine. **"Canon" is on that list too** — it's our internal shorthand for the
+  reference list; the site says "References" and links to `/references/`.
 
 ## Adding a sin