fix: await demonstrateUsage() to make example output deterministic

The doubled fire-and-forget calls caused non-deterministic interleaved
output that differed between node and browser environments. Single
awaited call produces consistent output in both.

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

Author: jacobshirley

packages/pki-lite-crypto-extended/examples/usage.ts

@@ -98,8 +98,4 @@ async function demonstrateUsage() {
     )
 }
 
-// Execute the demonstration
-demonstrateUsage().catch(console.error)
-
-// Run the demonstration
-demonstrateUsage().catch(console.error)
+await demonstrateUsage()

packages/pki-lite-crypto-extended/test/acceptance/__snapshots__/examples.spec.ts.snap

@@ -2,18 +2,9 @@
 
 exports[`Examples > usage 1`] = `
 "=== MD5 Hashing ===
-=== MD5 Hashing ===
 MD5: 65a8e27d8879283831b664bd8b7f0ad4
 
 === AES ECB Encryption ===
-MD5: 65a8e27d8879283831b664bd8b7f0ad4
-
-=== AES ECB Encryption ===
-Original: Secret message!!
-Decrypted: Secret message!!
-Match: true
-
-=== AES CBC (No Padding) ===
 Original: Secret message!!
 Decrypted: Secret message!!
 Match: true
@@ -24,12 +15,6 @@ Decrypted length: 16
 Data match: true
 
 === Standard Algorithms (Fallback) ===
-Original length: 16
-Decrypted length: 16
-Data match: true
-
-=== Standard Algorithms (Fallback) ===
-SHA-256: dffd6021bb2bd5b0af676290809ec3a53191dd81c7f70a4b28688a362182986f
 SHA-256: dffd6021bb2bd5b0af676290809ec3a53191dd81c7f70a4b28688a362182986f
 "
 `;