Skill request: MAUI/Mono gcdump-based managed heap collection for Android/iOS apps

## Problem
There's currently no skill in dotnet/skills focused on capturing managed memory dumps (GC dumps) from .NET MAUI apps running on Android and iOS devices, specifically for the Mono runtime environment. Existing skills such as `dump-collect` address CoreCLR/NativeAOT (.NET Core 3+), but not the gcdump workflow required for Mono-based MAUI scenarios.

## Request
- Add a new skill (e.g., `maui-gcdump-collect`) to document the steps and options for collecting managed memory dumps (using `gcdump`, `dotnet-gcdump`, or a supported alternative) from a **running** .NET MAUI app on **physical Android and iOS devices**.
- Highlight any tool/SDK/device requirements or constraints.
- Clarify whether host-side tools (e.g., `adb` for Android) or in-app diagnostics endpoints are needed.
- Provide troubleshooting guidance for device connectivity and permissions.
- Be explicit that this is for Mono/MAUI, and does not overlap with CoreCLR/NativeAOT crash/heap dump capture.

## Related Resource
This wiki page is the starting point for .NET MAUI profiling (including memory profiling):
- https://github.com/dotnet/maui/wiki/Profiling-.NET-MAUI-Apps

## Motivation
The intended use case is for troubleshooting managed heap issues (memory leaks, excessive GC, etc.) in testing on real MAUI devices, where gcdump is the required/mandated capture format (not OS crash dumps/core dumps, and not on emulators/simulators).

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Please triage as a feature request for new diagnostic documentation/skills relevant to device-based MAUI apps on Mono.

Read the existing `dump-collect` skill and the linked .NET MAUI Profiling wiki page first. Determine the supported gcdump workflow for running Mono-based MAUI apps on physical Android and iOS devices, including tools, device access, and constraints. Done means a new skill clearly documents collection, troubleshooting, and its distinction from CoreCLR/NativeAOT dump capture.

Written by the indexing model from the issue text.