Major refactoring: UUID-based storage, streaming architecture, and CLI improvements

This commit represents a significant architectural overhaul of vaultik:

Database Schema Changes:
- Switch files table to use UUID primary keys instead of path-based keys
- Add UUID primary keys to blobs table for immediate chunk association
- Update all foreign key relationships to use UUIDs
- Add comprehensive schema documentation in DATAMODEL.md
- Add SQLite busy timeout handling for concurrent operations

Streaming and Performance Improvements:
- Implement true streaming blob packing without intermediate storage
- Add streaming chunk processing to reduce memory usage
- Improve progress reporting with real-time metrics
- Add upload metrics tracking in new uploads table

CLI Refactoring:
- Restructure CLI to use subcommands: snapshot create/list/purge/verify
- Add store info command for S3 configuration display
- Add custom duration parser supporting days/weeks/months/years
- Remove old backup.go in favor of enhanced snapshot.go
- Add --cron flag for silent operation

Configuration Changes:
- Remove unused index_prefix configuration option
- Add support for snapshot pruning retention policies
- Improve configuration validation and error messages

Testing Improvements:
- Add comprehensive repository tests with edge cases
- Add cascade delete debugging tests
- Fix concurrent operation tests to use SQLite busy timeout
- Remove tolerance for SQLITE_BUSY errors in tests

Documentation:
- Add MIT LICENSE file
- Update README with new command structure
- Add comprehensive DATAMODEL.md explaining database schema
- Update DESIGN.md with UUID-based architecture

Other Changes:
- Add test-config.yml for testing
- Update Makefile with better test output formatting
- Fix various race conditions in concurrent operations
- Improve error handling throughout

internal/cli/entry_test.go

@@ -18,7 +18,7 @@ func TestCLIEntry(t *testing.T) {
 	}
 
 	// Verify all subcommands are registered
-	expectedCommands := []string{"backup", "restore", "prune", "verify", "fetch"}
+	expectedCommands := []string{"snapshot", "store", "restore", "prune", "verify", "fetch"}
 	for _, expected := range expectedCommands {
 		found := false
 		for _, cmd := range cmd.Commands() {
@@ -32,19 +32,24 @@ func TestCLIEntry(t *testing.T) {
 		}
 	}
 
-	// Verify backup command has proper flags
-	backupCmd, _, err := cmd.Find([]string{"backup"})
+	// Verify snapshot command has subcommands
+	snapshotCmd, _, err := cmd.Find([]string{"snapshot"})
 	if err != nil {
-		t.Errorf("Failed to find backup command: %v", err)
+		t.Errorf("Failed to find snapshot command: %v", err)
 	} else {
-		if backupCmd.Flag("config") == nil {
-			t.Error("Backup command missing --config flag")
-		}
-		if backupCmd.Flag("daemon") == nil {
-			t.Error("Backup command missing --daemon flag")
-		}
-		if backupCmd.Flag("cron") == nil {
-			t.Error("Backup command missing --cron flag")
+		// Check snapshot subcommands
+		expectedSubCommands := []string{"create", "list", "purge", "verify"}
+		for _, expected := range expectedSubCommands {
+			found := false
+			for _, subcmd := range snapshotCmd.Commands() {
+				if subcmd.Use == expected || subcmd.Name() == expected {
+					found = true
+					break
+				}
+			}
+			if !found {
+				t.Errorf("Expected snapshot subcommand '%s' not found", expected)
+			}
 		}
 	}
 }