File > Set Dev Directory throws on the render thread for a relative, ~ or quoted path #478

What's wrong

The "Set Dev Directory" popup callback (ProjectDirector/ProjectDirector.cs:876-885) passes whatever the user typed straight to AbsoluteDirectoryPath.Create<AbsoluteDirectoryPath>(result). The only guard is string.IsNullOrEmpty.

With ktsu.Semantics.Paths 5.11.0 (the pinned version), these inputs all throw ArgumentException: Cannot convert "..." to AbsoluteDirectoryPath:

• dev (relative)
• ~/dev
• " /tmp/x" (leading space)
• "\"C:\\dev\"" (quoted)

The callback runs from PopupSetDevDirectory.ShowIfOpen() inside Tick (ProjectDirector.cs:684), which is the render thread. Nothing there catches the exception, so it escapes the render loop and takes the app down. #440 and #444 treat a throw on the render thread the same way.

Failure scenario

On Windows, a user copies their dev folder with Explorer's "Copy as path", which wraps it in quotes ("C:\dev"). They paste it into the popup and press OK, and the app crashes. Typing ~/dev or a relative folder name does the same.

Suggested fix

• Trim whitespace and a surrounding pair of quotes from the input.
• Optionally expand a leading ~ to the user profile directory.
• Validate with Path.IsPathFullyQualified, or catch ArgumentException. On rejection, QueueLog the reason and keep the previous DevDirectory.

Acceptance criteria

• Entering dev, "C:\dev", ~/dev or " C:\dev " never throws.
• Each input either sets a valid absolute DevDirectory (for the quoted and padded cases) or leaves it unchanged and logs why the input was refused.