Add lazy-auth-server example (#679)

Adds an example MCP App server demonstrating lazy (on-demand) OAuth:
the server connects and lists tools without authentication, and only
prompts for auth when a protected tool is called, by responding 401
with a WWW-Authenticate header pointing at protected-resource metadata.

- Public `show_auth_button` app calls the protected `get_secret` tool
  via callServerTool; the host runs the OAuth flow on 401 and retries
- Embedded mock authorization server (authorization-code + PKCE,
  short-lived HS256 tokens, refresh + session revocation) so the whole
  flow runs from a single process
- TTL-scoped endpoint paths (/ttl/<seconds>/mcp) let slow or automated
  clients request longer-lived tokens per connection, threaded through
  OAuth via RFC 8707 resource indicators
- `elicit_url` / `elicit_by_error` tools demonstrating URL elicitation

examples/lazy-auth-server/vite.config.ts

@@ -0,0 +1,24 @@
+import { defineConfig } from "vite";
+import { viteSingleFile } from "vite-plugin-singlefile";
+
+const INPUT = process.env.INPUT;
+if (!INPUT) {
+  throw new Error("INPUT environment variable is not set");
+}
+
+const isDevelopment = process.env.NODE_ENV === "development";
+
+export default defineConfig({
+  plugins: [viteSingleFile()],
+  build: {
+    sourcemap: isDevelopment ? "inline" : undefined,
+    cssMinify: !isDevelopment,
+    minify: !isDevelopment,
+
+    rollupOptions: {
+      input: INPUT,
+    },
+    outDir: "dist",
+    emptyOutDir: false,
+  },
+});