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

Makefile

@@ -11,7 +11,7 @@ LDFLAGS := -X 'git.eeqj.de/sneak/vaultik/internal/globals.Version=$(VERSION)' \
            -X 'git.eeqj.de/sneak/vaultik/internal/globals.Commit=$(GIT_REVISION)'
 
 # Default target
-all: test
+all: vaultik
 
 # Run tests
 test: lint fmt-check
@@ -39,8 +39,8 @@ lint:
 	golangci-lint run
 
 # Build binary
-build:
-	go build -ldflags "$(LDFLAGS)" -o vaultik ./cmd/vaultik
+vaultik: internal/*/*.go cmd/vaultik/*.go
+	go build -ldflags "$(LDFLAGS)" -o $@ ./cmd/vaultik
 
 # Clean build artifacts
 clean: