Add shared SDC app shell (SdcTopBar + ApiSettings + unified credentials)

Workstream D: a shared top bar for the SDC tool suite — app name (left), API
settings cog, and the suite app directory (grid) — composed on the existing
TopBar. Adds an ApiSettings dialog and sdc_api_key/sdc_api_endpoint credential
helpers (shared once across all tools, with legacy-key migration). lucide-react
becomes a peer dependency. Bump to 0.2.0.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

vite.lib.config.ts

@@ -34,9 +34,9 @@ export default defineConfig({
       fileName: () => 'index.js',
     },
     rollupOptions: {
-      // React is a peer dep — externalise it (and the automatic JSX runtime) to avoid bundling a
-      // second copy. Everything else (clsx, tailwind-merge, @floating-ui) is small and bundled.
-      external: ['react', 'react-dom', 'react/jsx-runtime'],
+      // React + lucide-react are peer deps (consumer apps already have them) — externalise to avoid
+      // bundling a second copy. Everything else (clsx, tailwind-merge, @floating-ui) is small and bundled.
+      external: ['react', 'react-dom', 'react/jsx-runtime', 'lucide-react'],
       output: { preserveModules: false },
     },
     sourcemap: true,