delete the landing app

Built and shipped from somewhere else now, so this copy was dead weight that still
carried its own third copy of the palette — `duck-teal` had three different definitions
across three apps, and this was one of them.

Removed: `src/apps/landing`, `scripts/build/landing.ts`, the `build:landing` script,
and the tree entry in CLAUDE.md.

`/landing-page-data` STAYS and is unrelated despite the name — it is the API the
sign-in screen asks whether registration is open. Worth saying because a grep for
"landing" hits both and only one of them was meant.

Nothing imported from the app. tsgo clean, frontend builds, the live app serves.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

scripts/build/landing.ts

@@ -1,55 +0,0 @@
-#!/usr/bin/env bun
-import plugin from 'bun-plugin-tailwind';
-import { existsSync } from 'fs';
-import { rm } from 'fs/promises';
-import path from 'path';
-
-const outdir = path.join(process.cwd(), 'dist_landing');
-
-if (existsSync(outdir)) {
-  console.log(`🗑️ Cleaning previous build at ${outdir}`);
-  await rm(outdir, { recursive: true, force: true });
-}
-
-console.log('\n🚀 Starting landing page build...\n');
-
-const start = performance.now();
-
-const entrypoints = [...new Bun.Glob('**.html').scanSync('src/apps/landing')]
-  .map((a) => path.resolve('src/apps/landing', a))
-  .filter((dir) => !dir.includes('node_modules'));
-console.log(`📄 Found ${entrypoints.length} HTML ${entrypoints.length === 1 ? 'file' : 'files'} to process\n`);
-
-const formatFileSize = (bytes: number): string => {
-  const units = ['B', 'KB', 'MB', 'GB'];
-  let size = bytes;
-  let unitIndex = 0;
-  while (size >= 1024 && unitIndex < units.length - 1) {
-    size /= 1024;
-    unitIndex++;
-  }
-  return `${size.toFixed(2)} ${units[unitIndex]}`;
-};
-
-const result = await Bun.build({
-  entrypoints,
-  outdir,
-  plugins: [plugin],
-  minify: true,
-  target: 'browser',
-  sourcemap: 'linked',
-  define: {
-    'process.env.NODE_ENV': JSON.stringify('production'),
-  },
-});
-
-const end = performance.now();
-
-const outputTable = result.outputs.map((output) => ({
-  File: path.relative(process.cwd(), output.path),
-  Type: output.kind,
-  Size: formatFileSize(output.size),
-}));
-
-console.table(outputTable);
-console.log(`\n✅ Build completed in ${(end - start).toFixed(2)}ms\n`);