Scaffold Chart Sins site with Astro + build-time Vega-Lite

Set up the static-site tech stack: Astro 5 with Markdown content
collections, Vega-Lite specs rendered to static SVG at build time
(zero client JS), plain scoped CSS, and a GitHub Pages deploy workflow.

Includes three sample sins (truncated y-axis, dual-axis deception,
pie chart overload), each with a bad and fixed chart spec, plus a
gallery index and per-sin detail pages.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XPEvmMbac2fCvKXpQcovj8

src/lib/charts.ts

@@ -0,0 +1,29 @@
+import type { TopLevelSpec } from 'vega-lite';
+
+// Eagerly load every Vega-Lite spec in src/charts/ at build time so pages can
+// look one up by its basename (e.g. "dual-axis-bad").
+const modules = import.meta.glob<{ default: TopLevelSpec }>('../charts/*.json', {
+  eager: true,
+});
+
+const specsByName = new Map<string, TopLevelSpec>();
+for (const [path, mod] of Object.entries(modules)) {
+  const name = path.split('/').pop()!.replace(/\.json$/, '');
+  specsByName.set(name, mod.default);
+}
+
+/** Look up a Vega-Lite spec by basename; throws at build time if missing. */
+export function getChartSpec(name: string): TopLevelSpec {
+  const spec = specsByName.get(name);
+  if (!spec) {
+    throw new Error(
+      `Chart spec "${name}" not found in src/charts/. Available: ${[...specsByName.keys()].join(', ')}`,
+    );
+  }
+  return spec;
+}
+
+/** Render a 1–5 severity as flame glyphs for display. */
+export function severityFlames(severity: number): string {
+  return '🔥'.repeat(severity) + '·'.repeat(Math.max(0, 5 - severity));
+}