feat: add fswatch, sysinfo, and udp demo scripts plus reorder manual sidebar links

Add three new example scripts demonstrating the fswatch, sysinfo, and udp modules with file watching, system metrics, and UDP echo server/client patterns. Reorder the manual API sidebar navigation to list modules alphabetically, removing deprecated entries like websocket, tls, net, json, regex, jinja, os, signal, subprocess, sqlite, and timer while adding argparse, dataset, fswatch, and html.

example/sysinfo_demo.wren

@@ -0,0 +1,65 @@
+// retoor <retoor@molodetz.nl>
+
+import "sysinfo" for SysInfo
+
+var formatBytes = Fn.new { |bytes|
+    if (bytes < 1024) return "%(bytes) B"
+    if (bytes < 1024 * 1024) return "%(((bytes / 1024) * 10).floor / 10) KB"
+    if (bytes < 1024 * 1024 * 1024) return "%(((bytes / 1024 / 1024) * 10).floor / 10) MB"
+    return "%(((bytes / 1024 / 1024 / 1024) * 10).floor / 10) GB"
+}
+
+System.print("=== SysInfo Module Demo ===\n")
+
+System.print("--- System Information ---")
+System.print("Hostname: %(SysInfo.hostname)")
+System.print("Uptime: %(SysInfo.uptime) seconds")
+
+System.print("\n--- Memory Information ---")
+var total = SysInfo.totalMemory
+var free = SysInfo.freeMemory
+var used = total - free
+var resident = SysInfo.residentMemory
+var constrained = SysInfo.constrainedMemory
+
+System.print("Total: %(formatBytes.call(total))")
+System.print("Free: %(formatBytes.call(free))")
+System.print("Used: %(formatBytes.call(used))")
+System.print("Process RSS: %(formatBytes.call(resident))")
+if (constrained > 0) {
+    System.print("Constrained: %(formatBytes.call(constrained))")
+}
+
+System.print("\n--- CPU Information ---")
+var cpus = SysInfo.cpuInfo
+System.print("CPU Count: %(cpus.count)")
+
+for (i in 0...cpus.count) {
+    var cpu = cpus[i]
+    System.print("  CPU %(i): %(cpu["model"]) @ %(cpu["speed"]) MHz")
+}
+
+System.print("\n--- Load Average ---")
+var load = SysInfo.loadAverage
+System.print("1 min: %(load[0])")
+System.print("5 min: %(load[1])")
+System.print("15 min: %(load[2])")
+
+System.print("\n--- Network Interfaces ---")
+var interfaces = SysInfo.networkInterfaces
+for (name in interfaces.keys) {
+    System.print("%(name):")
+    for (addr in interfaces[name]) {
+        System.print("  %(addr["family"]): %(addr["address"])")
+        System.print("    Internal: %(addr["internal"])")
+        System.print("    Netmask: %(addr["netmask"])")
+        System.print("    MAC: %(addr["mac"])")
+    }
+}
+
+System.print("\n--- High Resolution Timer ---")
+var t1 = SysInfo.hrtime
+var t2 = SysInfo.hrtime
+System.print("Time 1: %(t1) ns")
+System.print("Time 2: %(t2) ns")
+System.print("Delta: %(t2 - t1) ns")