fix(watcher): log swallowed config-load error instead of discarding it

[Caesarsage]

Description

TriggerImport in pkg/watcher/executor.go built an error with fmt.Errorf
on a config-load failure and then discarded the result, so the failure was
silently swallowed — nothing logged, nothing returned, execution continued
with an empty config path.

cfgPath, err := config.DefaultLocalConfigPath()
if err != nil {
    fmt.Errorf("Error while loading config: %s", err.Error())  // result discarded
}

Replaced it with a logged error (matching the [ERROR]/[WARN] style the rest
of the function already uses) and an early return, since there's no point
continuing without a config path.

So this also un-breaks go vet ./... for the whole module.

How verified

go vet ./... — now clean (previously reported the error above)
go build ./... and go test ./... pass

Surfaced while working on the CLI v2 mentorship. Refs #255

[Harsh4902]

Good to go.