Trigger the initial build immediately on startup

[bcremer]

before:

$ date '+%H:%M:%S'; ./CompileDaemon -work-delay=2000
16:34:10
2026/05/06 16:34:13 Running build commands!
2026/05/06 16:34:13 Build ok.

after:

$ date '+%H:%M:%S'; ./CompileDaemon -work-delay=2000
16:33:39
2026/05/06 16:33:39 Running build commands!
2026/05/06 16:33:39 Build ok.