style: apply gofmt across Go sources

Repo-wide gofmt sweep: const-block alignment, doc-comment spacing,
statement-after-brace fix in media.go, trailing blank lines. No
semantic changes — whitespace-insensitive diff is empty for every
file in this commit.

internal/services/book_matching.go

@@ -19,9 +19,9 @@ type BookMatch struct {
 	Confidence    float64   `json:"confidence"`
 	MatchMethod   string    `json:"match_method"`
 	// Display fields, filled during the family-lens pass in QueryBooks.
-	Title           string `json:"title"`
-	Author          string `json:"author"`
-	CoverImagePath  string `json:"cover_image_path"`
+	Title          string `json:"title"`
+	Author         string `json:"author"`
+	CoverImagePath string `json:"cover_image_path"`
 }
 
 // BookQueryRequest represents a book query from a device