Add PowerShell network device scanner with multi-subnet discovery and API endpoint detection

[Copilot]

Implements a PowerShell script for Windows 11 that discovers devices across multiple LAN subnets, identifies device types (IoT hubs, smart devices, security equipment), and detects exposed API endpoints.

Implementation

scripts/NetworkDeviceScanner.ps1 (837 lines)

• Multi-subnet scanning with CIDR auto-detection or manual specification
• Parallel ICMP-based host discovery (configurable concurrency, default 50)
• Port scanning across 42+ common API ports (80, 443, 8123, 8080, etc.)
• HTTP/HTTPS probing with header and content analysis for device fingerprinting
• Device type identification: Home Assistant, Shelly, Ubiquiti, Ajax, Synology, IP cameras
• Output formats: Table, List, JSON, CSV with export capability
• Self-signed certificate handling with proper callback restoration

scripts/README.md (402 lines)

• Usage examples, parameter reference, device identification matrix
• Performance tuning guidance for large networks

scripts/HANDOVER.md (213 lines)

• Testing scenarios and implementation notes

Key Technical Details

Performance optimization for large subnets:

# Use ArrayList instead of array concatenation to avoid O(n²) behavior
$ips = New-Object System.Collections.ArrayList
for ($i = $networkInt + 1; $i -lt $broadcastInt; $i++) {
    [void]$ips.Add([System.Net.IPAddress]::new($bytes).ToString())
}

Secure certificate validation:

try {
    if ($protocol -eq 'https') {
        $originalCallback = [System.Net.ServicePointManager]::ServerCertificateValidationCallback
        [System.Net.ServicePointManager]::ServerCertificateValidationCallback = {$true}
        # ... make requests ...
    }
}
finally {
    # Restore to prevent session-wide security impact
    if ($null -ne $originalCallback) {
        [System.Net.ServicePointManager]::ServerCertificateValidationCallback = $originalCallback
    }
}

Safe content truncation:

$fullContent = $reader.ReadToEnd()
$result.Content = $fullContent.Substring(0, [Math]::Min(4096, $fullContent.Length))

Original prompt

@develop-agent Task: I want to create a powershell script that will run on my windows 11 laptop. It needs to seach my local lan (mulitiole subnets) for all devices it can see. Then fins out what kind of device it is and look for API endpoints exposed by the device.
Devices can range from IOT hubs (eg home assistant) to IOT devices (shelly) or even security decices (Ubiquity, Ajax security hub with NVR and such).

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