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/selfupdate/state.go

@@ -12,13 +12,13 @@ const stateFileName = "update-state.json"
 
 // UpdateState tracks the last update attempt. Persisted to disk as audit log.
 type UpdateState struct {
-	Status          string `json:"status"`                   // "pending", "success", "failed"
+	Status          string `json:"status"` // "pending", "success", "failed"
 	PreviousVersion string `json:"previous_version"`
 	PreviousImage   string `json:"previous_image"`
 	TargetVersion   string `json:"target_version"`
 	TargetImage     string `json:"target_image"`
-	InitiatedAt     string `json:"initiated_at"`             // RFC3339
-	InitiatedBy     string `json:"initiated_by"`             // "manual" or "auto"
+	InitiatedAt     string `json:"initiated_at"` // RFC3339
+	InitiatedBy     string `json:"initiated_by"` // "manual" or "auto"
 	CompletedAt     string `json:"completed_at,omitempty"`
 	Error           string `json:"error,omitempty"`
 }