docs(design): remove SVG, use PNG logo only

SVG icon is no longer in use. public/logo.png (1024x1024 RGBA) is
the single logo asset. DESIGN.md updated accordingly: SVG snippet
removed, wordmark pattern and <head> references updated to PNG.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

node_modules/tailwindcss/scripts/release-channel.js

@@ -0,0 +1,18 @@
+// Given a version, figure out what the release channel is so that we can publish to the correct
+// channel on npm.
+//
+// E.g.:
+//
+//   1.2.3                  -> latest (default)
+//   0.0.0-insiders.ffaa88  -> insiders
+//   4.1.0-alpha.4          -> alpha
+
+let version =
+  process.argv[2] || process.env.npm_package_version || require('../package.json').version
+
+let match = /\d+\.\d+\.\d+-(.*)\.\d+/g.exec(version)
+if (match) {
+  console.log(match[1])
+} else {
+  console.log('latest')
+}