style: gofmt all packages (#4)

Applies gofmt to the 18 files that were already unformatted at HEAD (pre-existing debt — 122 insertions / 122 deletions, whitespace plus import-block reorderings only; `git diff -w` confirms no semantic changes).

Kept on its own branch so the functional change set (see the review-hardening PR) stays reviewable without formatting noise.

Verified: go build, go vet, go test ./... pass on this branch; a merge simulation with the functional branch produces a clean 3-way merge with all tests green.
Reviewed-on: #4
Co-authored-by: David Gwilliam <dhgwilliam@gmail.com>
Co-committed-by: David Gwilliam <dhgwilliam@gmail.com>

internal/db/metrics.go

@@ -11,7 +11,7 @@ type MetricsSnapshot struct {
 	PendingReflections  int
 	ThreadsByStatus     map[string]int
 	Peers               int
-	ByOriginNode        map[string]int // node_id → observation count
+	ByOriginNode        map[string]int   // node_id → observation count
 	KnowledgeVector     map[string]int64 // node_id → max hcl
 	EarliestObservation string
 }
@@ -105,4 +105,4 @@ func (k *KnoxDB) MetricsSnapshot() (*MetricsSnapshot, error) {
 		return nil, err
 	}
 	return s, nil
-}
+}