feat: Add crash dump capture and analysis to --debug-output

[lei9444]

Description

When a WinUI 3 app crashes during winapp run --debug-output, the previous output only showed a bare exception code and address. This PR adds automatic crash dump capture and in-process analysis using ClrMD (Microsoft.Diagnostics.Runtime) — no external tools required.

How it works

1. First-chance context capture — When a critical first-chance exception (Access Violation, Stack Overflow, CLR/C++ exception) fires, the faulting thread's CONTEXT is saved via GetThreadContext. At this point the context still points to user code — before WinUI's FailFastWithStowedExceptions replaces the stack.
2. Crash dump on second-chance — On second-chance exception (actual crash), MiniDumpWriteDump is called with the saved first-chance context as MINIDUMP_EXCEPTION_INFORMATION, preserving the original crash location in the dump. For Stack Overflow (always fatal in .NET, no second-chance follows), the dump is captured immediately at first-chance.
3. ClrMD analysis — The dump is analyzed in-process using Microsoft.Diagnostics.Runtime:

• First checks thread.CurrentException for managed exceptions
• Falls back to heap scanning for exceptions cleared by WinUI's FailFast
• Detects Stack Overflow via deep recursion patterns (>100 repeated frames)

4. No external dependencies — Unlike approaches based on CDB/WinDbg or procdump, this works out of the box with zero tool installation. For native-only crashes (no CLR runtime in dump), the dump path is printed with WinDbg instructions as fallback.

Output layering

Terminal: Crash summary: faulting symbol, module, source file:line, compact stack (framework frames collapsed)
Log file: All OutputDebugString messages, first-chance exceptions, full thread stacks with module names
Dump file: Full memory minidump for deep analysis with WinDbg or Visual Studio

Usage Example

winapp run <output-folder> --debug-output

Related Issue

Type of Change

• ✨ New feature

Checklist

• Tested locally on Windows
• Main README.md updated (if applicable)
• docs/usage.md updated (if CLI commands changed)
• Language-specific guides updated (if applicable)
• Sample projects updated to reflect changes (if applicable)

Screenshots / Demo

AI Description

This PR introduces automatic crash dump capture and analysis during winapp run --debug-output. When a WinUI 3 app encounters critical exceptions, a minidump is generated, and the crash is analyzed in-process using ClrMD, eliminating the need for external tools. Users can utilize it as follows:

winapp run  --debug-output

Breaking Change: None.

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Build Metrics Report

Binary Sizes

Artifact	Baseline	Current	Delta
CLI (ARM64)	29.22 MB	30.34 MB	📈 +1.11 MB (+3.81%)
CLI (x64)	29.67 MB	30.71 MB	📈 +1.04 MB (+3.51%)
MSIX (ARM64)	12.32 MB	12.81 MB	📈 +501.8 KB (+3.98%)
MSIX (x64)	13.10 MB	13.59 MB	📈 +502.2 KB (+3.74%)
NPM Package	25.63 MB	26.63 MB	📈 +1022.6 KB (+3.90%)
NuGet Package	25.71 MB	26.71 MB	📈 +1.01 MB (+3.92%)

Test Results

✅ 718 passed out of 718 tests in 411.0s (+4 tests, -3.7s vs. baseline)

Test Coverage

❌ 20.8% line coverage, 36.5% branch coverage · ⚠️ -0.2% vs. baseline

CLI Startup Time

40ms median (x64, winapp --version) · ✅ no change vs. baseline

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Updated 2026-04-09 05:06:00 UTC · commit ccd07b8 · workflow run

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Pull request overview

Copilot reviewed 27 out of 35 changed files in this pull request and generated 8 comments.

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