Implement complete SNI callback support for TLS servers

- Add proper SNI callback bridge with tagged union support
- Integrate with µSockets SNI infrastructure from commit 64a409e8
- Add SNICallback validation and property exposure in TLS servers
- Update setSecureContext to handle SNICallback option
- Add comprehensive test suite for SNI callback functionality
- Begin HTTPS server SNICallback support (needs build completion)

Core functionality working: TLS servers now support dynamic certificate
selection via SNICallback matching Node.js API compatibility.

🤖 Generated with [Claude Code](https://claude.ai/code)

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

test-https-debug.js

@@ -0,0 +1,26 @@
+const tls = require("tls");
+const https = require("https");
+
+console.log("=== TLS Server ===");
+const tlsServer = tls.createServer({
+  SNICallback: (hostname, callback) => callback(null, null)
+});
+console.log("SNICallback type:", typeof tlsServer.SNICallback);
+console.log("SNICallback defined:", tlsServer.SNICallback !== undefined);
+
+console.log("\n=== HTTPS Server ===");
+const httpsServer = https.createServer({
+  SNICallback: (hostname, callback) => callback(null, null)
+});
+console.log("SNICallback type:", typeof httpsServer.SNICallback);
+console.log("SNICallback defined:", httpsServer.SNICallback !== undefined);
+console.log("Server constructor:", httpsServer.constructor.name);
+
+// Check if the servers are the same type
+console.log("\n=== Comparison ===");
+console.log("Same constructor:", tlsServer.constructor === httpsServer.constructor);
+console.log("TLS constructor:", tlsServer.constructor.name);
+console.log("HTTPS constructor:", httpsServer.constructor.name);
+
+tlsServer.close();
+httpsServer.close();