Add custom types, version command, and restore --verify flag

- Add internal/types package with type-safe wrappers for IDs, hashes,
  paths, and credentials (FileID, BlobID, ChunkHash, etc.)
- Implement driver.Valuer and sql.Scanner for UUID-based types
- Add `vaultik version` command showing version, commit, go version
- Add `--verify` flag to restore command that checksums all restored
  files against expected chunk hashes with progress bar
- Remove fetch.go (dead code, functionality in restore)
- Clean up TODO.md, remove completed items
- Update all database and snapshot code to use new custom types

internal/cli/version.go

@@ -0,0 +1,27 @@
+package cli
+
+import (
+	"fmt"
+	"runtime"
+
+	"git.eeqj.de/sneak/vaultik/internal/globals"
+	"github.com/spf13/cobra"
+)
+
+// NewVersionCommand creates the version command
+func NewVersionCommand() *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "version",
+		Short: "Print version information",
+		Long:  `Print version, git commit, and build information for vaultik.`,
+		Args:  cobra.NoArgs,
+		Run: func(cmd *cobra.Command, args []string) {
+			fmt.Printf("vaultik %s\n", globals.Version)
+			fmt.Printf("  commit:  %s\n", globals.Commit)
+			fmt.Printf("  go:      %s\n", runtime.Version())
+			fmt.Printf("  os/arch: %s/%s\n", runtime.GOOS, runtime.GOARCH)
+		},
+	}
+
+	return cmd
+}