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.

cmd/server/tests/contract_pins_test.go

@@ -123,7 +123,7 @@ func createContractFixture(t *testing.T, setup *TestServerSetup) contractFixture
 	media, err := setup.DB.CreateMediaItem(ctx, database.CreateMediaItemParams{
 		LibraryID: pgtype.UUID{Bytes: libUUID, Valid: true},
 		Title:     itemTitle,
-		Authors:  []string{"Test Contract Author"},
+		Authors:   []string{"Test Contract Author"},
 		Series:    pgtype.Text{String: seriesName, Valid: true},
 		Genre:     pgtype.Text{String: "Science Fiction", Valid: true},
 		FilePath:  "/tmp/contract-test-item.epub",