Finish the lint remediation: script/cibuild exits 0 (closes #61)

Clears the final 80 golangci-lint findings under the canonical
.golangci.yml (sha256 021cc83f4e6fc7c31b95b34b846723dfcf20b66b7baeea1dc40406e643346bcb),
taking the repo from red to green: script/cibuild exits 0.

- wsl_v5 (60): blank line above defer/go statements sharing no variable
  with the line above; blank-line-only diff.
- sqlclosecheck (10): the package-local CloseRows helper hid the close
  from the analyzer. Helper removed; all 18 call sites now defer an
  inline rows.Close(), preserving the fatal-on-close-error path. No
  resource leak existed - the rows were always being closed.
- prealloc (3): append targets given a starting capacity.
- revive (3): package-name findings suppressed with per-site directives
  pending the naming decision tracked in #76.

No gosec suppressions are needed under the pinned linter. .golangci.yml,
Dockerfile, Makefile, .gitea/ and script/ are byte-identical to main.

Verified with script/cibuild (digest-pinned golangci-lint v2.12.2), not
make check - the latter resolves the linter from PATH and is not a
trustworthy gate here; see #78.

Closes #59.

internal/vaultik/integration_test.go

@@ -134,6 +134,7 @@ func (m *MockStorer) ListStream(
 	_ context.Context, prefix string,
 ) <-chan storage.ObjectInfo {
 	ch := make(chan storage.ObjectInfo)
+
 	go func() {
 		defer close(ch)
 
@@ -326,6 +327,7 @@ func TestEndToEndBackup(t *testing.T) {
 	db, err := database.New(ctx, ":memory:")
 
 	require.NoError(t, err)
+
 	defer func() {
 		err := db.Close()
 		if err != nil {
@@ -411,6 +413,7 @@ func TestBackupAndVerify(t *testing.T) {
 	db, err := database.New(ctx, ":memory:")
 
 	require.NoError(t, err)
+
 	defer func() {
 		err := db.Close()
 		if err != nil {
@@ -968,6 +971,7 @@ func TestDedupOnlySnapshotRestores(t *testing.T) {
 
 	env := setupDedupBackupEnv(
 		ctx, t, fs, storeDir, dbPath, chunkSize, maxBlobSize)
+
 	defer func() { _ = env.db.Close() }()
 
 	cfg, storer, repos, sm := env.cfg, env.storer, env.repos, env.sm