Fix: Return Success=false for cancelled operations

[Copilot]

When users cancel form inputs or command arguments, the code was returning Success = true with an error message—semantically contradictory since ProjectCommanderHub nullifies error messages when Success = true (line 67):

annotation.ErrorMessage = success ? null : errorMessage;

Changes

• Startup form cancellation (line 127): Success = true → Success = false
• Command argument cancellation (line 246): Success = true → Success = false

Aligns cancellation handling with other error conditions throughout the codebase that correctly return Success = false.

---

💬 We'd love your input! Share your thoughts on Copilot coding agent in our 2 minute survey.