Speed up the vaultik and database package tests (closes #235)

In the Dockerfile test phase, internal/vaultik spent 23.6s of 31.9s in
36 tests run one at a time. 24 of them were serial only because they
call log.Initialize; they now call it before t.Parallel(), so the
logger is replaced before any parallel test runs. The 12 still serial
change the umask, TMPDIR, os.Stderr or time.Local.

TestLargeDatasets took 8.4s of the 9.8s internal/database run by
committing each of its 1,500 inserts on its own; it now makes them in
one transaction. TestDedupOnlySnapshotRestores gives its second backup
its own snapshot name instead of sleeping 1.1s for a new snapshot ID.

Model: opus-5-5

internal/vaultik/fault_injection_test.go

@@ -38,11 +38,9 @@ import (
 // (https://git.eeqj.de/sneak/vaultik/issues/130) and is not re-tested
 // here; these tests target the layers above the backend.
 //
-// The tests run serially, not with t.Parallel: each calls
-// log.Initialize, which replaces the package-global logger, and a
-// backup or restore running concurrently reads that same logger. Under
-// -race the two collide. Running one at a time is the same choice
-// prune_count_test.go already makes for the same reason.
+// log.Initialize replaces the package-global logger that a running
+// backup or restore reads, so each test calls it before t.Parallel,
+// while no parallel test is running yet.
 
 const (
 	faultChunkSize   = int64(64 * 1024)
@@ -165,17 +163,19 @@ func newReaderVaultik(
 // Scenario 3: a stored blob's bytes are flipped before restore reads
 // them. Restore must fail loudly, and no file must be left on the
 // restore target holding corrupt content.
-//
-//nolint:paralleltest // installs the global logger via log.Initialize
 func TestRestoreRejectsCorruptBlob(t *testing.T) {
+	log.Initialize(log.Config{})
+	t.Parallel()
+
 	assertRestoreRejectsDamagedBlob(t, faultstore.GetCorrupt, "corrupt")
 }
 
 // Scenario 4: a stored blob is truncated before restore reads it. Same
 // contract as the corrupt case.
-//
-//nolint:paralleltest // installs the global logger via log.Initialize
 func TestRestoreRejectsTruncatedBlob(t *testing.T) {
+	log.Initialize(log.Config{})
+	t.Parallel()
+
 	assertRestoreRejectsDamagedBlob(t, faultstore.GetTruncate, "truncated")
 }
 
@@ -188,7 +188,6 @@ func assertRestoreRejectsDamagedBlob(
 	t *testing.T, fault faultstore.GetFault, name string,
 ) {
 	t.Helper()
-	log.Initialize(log.Config{})
 
 	fs := afero.NewOsFs()
 	tempDir := t.TempDir()
@@ -232,10 +231,9 @@ func assertRestoreRejectsDamagedBlob(
 
 // Scenario 6: the backend accepts blob uploads and reports success but
 // stores nothing. verify --deep must catch it.
-//
-//nolint:paralleltest // installs the global logger via log.Initialize
 func TestDeepVerifyCatchesLyingBackend(t *testing.T) {
 	log.Initialize(log.Config{})
+	t.Parallel()
 
 	fs := afero.NewOsFs()
 	tempDir := t.TempDir()
@@ -285,10 +283,9 @@ func TestDeepVerifyCatchesLyingBackend(t *testing.T) {
 // Scenario 1a: a blob upload fails partway through. The interrupted run
 // must not record the blob as uploaded, must not reference it from the
 // snapshot, and must leave no blob object at the destination.
-//
-//nolint:paralleltest // installs the global logger via log.Initialize
 func TestInterruptedBlobUploadRecordsNoUploadedBlob(t *testing.T) {
 	log.Initialize(log.Config{})
+	t.Parallel()
 
 	fs := afero.NewOsFs()
 	tempDir := t.TempDir()
@@ -361,10 +358,9 @@ func TestInterruptedBlobUploadRecordsNoUploadedBlob(t *testing.T) {
 // chunks in a blob that was actually uploaded, so the retry re-chunks and
 // re-uploads the affected data instead of silently referencing data that
 // never reached storage.
-//
-//nolint:paralleltest // installs the global logger via log.Initialize
 func TestBackupRetryAfterInterruptedUploadIsRestorable(t *testing.T) {
 	log.Initialize(log.Config{})
+	t.Parallel()
 
 	fs := afero.NewOsFs()
 	tempDir := t.TempDir()
@@ -426,10 +422,9 @@ func TestBackupRetryAfterInterruptedUploadIsRestorable(t *testing.T) {
 // covered by TestBackupCompletesOnlyAfterMetadataExport
 // (https://git.eeqj.de/sneak/vaultik/issues/177); this test exercises the
 // lower-level export path in isolation.
-//
-//nolint:paralleltest // installs the global logger via log.Initialize
 func TestBackupSurvivesMetadataExportInterruption(t *testing.T) {
 	log.Initialize(log.Config{})
+	t.Parallel()
 
 	fs := afero.NewOsFs()
 	tempDir := t.TempDir()
@@ -509,10 +504,9 @@ func TestBackupSurvivesMetadataExportInterruption(t *testing.T) {
 // destination. Rerunning the backup must then prune the incomplete
 // snapshot, produce a snapshot whose destination metadata and local index
 // agree, and restore. See https://git.eeqj.de/sneak/vaultik/issues/177.
-//
-//nolint:paralleltest // installs the global logger via log.Initialize
 func TestBackupCompletesOnlyAfterMetadataExport(t *testing.T) {
 	log.Initialize(log.Config{})
+	t.Parallel()
 
 	fs := afero.NewOsFs()
 	tempDir := t.TempDir()
@@ -685,10 +679,9 @@ func faultScannerFactory(
 // Scenario 5: the restore target runs out of space mid-file. Restore
 // must fail with an out-of-space error, and must not leave a truncated
 // file at the target path presenting as a complete restore.
-//
-//nolint:paralleltest // installs the global logger via log.Initialize
 func TestRestoreReportsDiskFull(t *testing.T) {
 	log.Initialize(log.Config{})
+	t.Parallel()
 
 	osFS := afero.NewOsFs()
 	tempDir := t.TempDir()