Remediate all lint findings under the canonical golangci-lint config

Fix every finding surfaced by the canonical .golangci.yml with
golangci-lint v2.12.2 (refs #61), behavior-preserving throughout:

- err113: dynamic errors replaced with package-level sentinels and %w
  wrapping; direct comparisons converted to errors.Is
- goprintffuncname: printf-style helpers renamed with an f suffix
  (ui.Writer message methods, cli.ReportErrorf, database.Fatalf,
  vaultik stdoutf) and all call sites updated
- revive: stuttering type names renamed (blob.Handler, blob.WithReader,
  blob.ChunkPosition, storage.URL, storage.Info), doc comments added,
  unused parameters blanked, package comments added
- contextcheck/noctx: ctx threaded through blob.Packer
  (AddChunk/Flush/FinalizeBlob/PackChunks) and scanner call sites;
  context-aware exec and sql variants used
- funlen/cyclop/gocognit/nestif/dupl: oversized or duplicated
  functions split into focused helpers across production and test code
- paralleltest/tparallel/thelper/usetesting/testpackage: tests
  parallelized where safe (global log.Initialize kept in the serial
  phase), helpers marked, t.TempDir adopted, external test packages
  where only exported API is used
- gosec: integer conversions clamped or justified, header timeouts
  added, remaining findings suppressed with per-site justifications
- mnd/goconst/lll/wsl_v5/nlreturn/noinlineerr/errcheck and other
  mechanical findings fixed directly

Remove the deprecated log.LogOptions alias (callers migrated to
log.Options). make check is green.

internal/cli/entry_test.go

@@ -1,14 +1,18 @@
-package cli
+package cli_test
 
 import (
 	"testing"
+
+	"sneak.berlin/go/vaultik/internal/cli"
 )
 
 // TestCLIEntry ensures the CLI can be imported and basic initialization works
 func TestCLIEntry(t *testing.T) {
+	t.Parallel()
+
 	// This test primarily serves as a compilation test
 	// to ensure all imports resolve correctly
-	cmd := NewRootCommand()
+	cmd := cli.NewRootCommand()
 	if cmd == nil {
 		t.Fatal("NewRootCommand() returned nil")
 	}
@@ -18,7 +22,9 @@ func TestCLIEntry(t *testing.T) {
 	}
 
 	// Verify all subcommands are registered
-	expectedCommands := []string{"config", "snapshot", "prune", "info", "version", "remote", "database"}
+	expectedCommands := []string{
+		"config", "snapshot", "prune", "info", "version", "remote", "database",
+	}
 	for _, expected := range expectedCommands {
 		found := false
 
@@ -41,7 +47,9 @@ func TestCLIEntry(t *testing.T) {
 		t.Errorf("Failed to find snapshot command: %v", err)
 	} else {
 		// Check snapshot subcommands
-		expectedSubCommands := []string{"create", "list", "purge", "verify", "remove", "restore"}
+		expectedSubCommands := []string{
+			"create", "list", "purge", "verify", "remove", "restore",
+		}
 		for _, expected := range expectedSubCommands {
 			found := false