Fix: pack with --self-contained won't overwrite dupe files from runtime like resources.pri

[zateutsch]

fixes #548

Generalized fix for this issue - any file that has a dupe in the dest directory will not be copied over from the runtime.

[Copilot]

Pull request overview

Fixes a --self-contained packaging bug (issue #548) where runtime files extracted from the Windows App SDK MSIX would overwrite the app's own files in the staging directory — most importantly resources.pri (destroying MRT mappings like Assets\SplashScreen.png → Assets\SplashScreen.scale-200.png) and Assets\StoreLogo.png, causing install failures with 0x80070002. The fix generalizes to skip any runtime file whose destination already exists, preserving app precedence during the runtime bundling step that runs after PRI generation in both single-package and bundle flows.

Changes:

• In PrepareRuntimeForPackagingAsync, skip the copy when the destination file already exists in staging instead of overwriting it.
• Switch file.CopyTo from overwrite: true to overwrite: false and emit a debug message for each skipped file.

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[github-actions]

Build Metrics Report

Binary Sizes

Artifact	Baseline	Current	Delta
CLI (ARM64)	31.45 MB	31.45 MB	📈 +0.5 KB (+0.00%)
CLI (x64)	31.79 MB	31.79 MB	✅ 0.0 KB (0.00%)
MSIX (ARM64)	13.21 MB	13.21 MB	📉 -0.0 KB (-0.00%)
MSIX (x64)	14.05 MB	14.05 MB	📉 -0.0 KB (-0.00%)
NPM Package	27.50 MB	27.50 MB	📈 +0.5 KB (+0.00%)
NuGet Package	27.59 MB	27.59 MB	📈 +1.4 KB (+0.01%)
VS Code Extension	20.31 MB	20.31 MB	📈 +1.1 KB (+0.01%)

Test Results

✅ 1190 passed, 1 skipped out of 1191 tests in 514.5s (+4 tests, +86.2s vs. baseline)

Test Coverage

❌ 17.2% line coverage, 36.3% branch coverage · ✅ no change vs. baseline

CLI Startup Time

42ms median (x64, winapp --version) · ✅ -5ms vs. baseline

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Updated 2026-06-01 18:05:09 UTC · commit 8615433 · workflow run

[Jaylyn-Barbee]

LGTM