style: gofmt normalization — no logic changes

gofmt -w across the controller tree (46 files) so gofmt -l is empty — disarms the
formatting landmine where a targeted edit + accidental gofmt -w swept ~46 unrelated
files. Pure formatting: whitespace + gofmt's optional-semicolon removal in reflowed
inline closures. One doc comment reworded ('' -> 'the empty string') to avoid gofmt's
Go-1.19 doc-comment typographic substitition ('' -> curly quote) muddying its meaning.
No build/vet/test behavior change.

controller/internal/selftest/selftest.go

@@ -19,7 +19,7 @@ import (
 // CheckResult represents the outcome of a single self-test check.
 type CheckResult struct {
 	Name    string `json:"name"`
-	Status  string `json:"status"`  // "pass", "warn", "fail"
+	Status  string `json:"status"` // "pass", "warn", "fail"
 	Message string `json:"message"`
 }