Follow-ups from the v0.10.0 pre-release review (DPI window bounds, git busy key, unmerged status codes) #181

Lower-severity findings from the v0.10.0 pre-release review that were deliberately not fixed before the release. Everything the review rated medium or higher went into the pre-release PR instead.

1. Window bounds restore under per-monitor DPI (from #175)

RestoreWindowState (MainWindow.xaml.cs, called from OnLoaded) applies the saved Left/Top/Width/Height after the window is already shown on the primary monitor. It clamps them against SystemParameters.VirtualScreen*, which is in primary-monitor DIPs. Now that the app is per-monitor DPI aware (v2), two cases misbehave:

• Mixed-DPI setups: a saved position on a secondary monitor with a different scale triggers a DPI change and a resize while the window moves there. The saved size can drift from run to run, and the clamp can put the window in the wrong place.
• First run after upgrading: the bounds were saved by the system-DPI build, in a different coordinate space.

Cosmetic only; no data is lost. Likely fix: apply the bounds in SourceInitialized, or via SetWindowPlacement, before the window is first shown.

2. Git busy-slot key before RepoRoot resolves (from #177)

GitRepoKey falls back to WorkingFolder while RepoRoot is still null. For a brief window after launch, two panes of the same repo can therefore hold different keys and run git operations at the same time. The second one fails on index.lock; nothing is lost.

3. ParseStatusV2 shows every unmerged entry as "UU" (from #177)

AA, DU and UD are all shown as UU. Separately, paths that git C-quotes even with core.quotePath=false (those containing ", \, a tab or a newline) are displayed still quoted. File counts are unaffected.