Add exclude patterns, snapshot prune, and other improvements

- Implement exclude patterns with anchored pattern support:
  - Patterns starting with / only match from root of source dir
  - Unanchored patterns match anywhere in path
  - Support for glob patterns (*.log, .*, **/*.pack)
  - Directory patterns skip entire subtrees
  - Add gobwas/glob dependency for pattern matching
  - Add 16 comprehensive tests for exclude functionality

- Add snapshot prune command to clean orphaned data:
  - Removes incomplete snapshots from database
  - Cleans orphaned files, chunks, and blobs
  - Runs automatically at backup start for consistency

- Add snapshot remove command for deleting snapshots

- Add VAULTIK_AGE_SECRET_KEY environment variable support

- Fix duplicate fx module provider in restore command

- Change snapshot ID format to hostname_YYYY-MM-DDTHH:MM:SSZ

internal/cli/restore.go

@@ -8,7 +8,6 @@ import (
 	"git.eeqj.de/sneak/vaultik/internal/database"
 	"git.eeqj.de/sneak/vaultik/internal/globals"
 	"git.eeqj.de/sneak/vaultik/internal/log"
-	"git.eeqj.de/sneak/vaultik/internal/snapshot"
 	"git.eeqj.de/sneak/vaultik/internal/storage"
 	"github.com/spf13/cobra"
 	"go.uber.org/fx"
@@ -60,7 +59,6 @@ The age_secret_key must be configured in the config file for decryption.`,
 					Debug:   rootFlags.Debug,
 				},
 				Modules: []fx.Option{
-					snapshot.Module,
 					fx.Provide(fx.Annotate(
 						func(g *globals.Globals, cfg *config.Config, repos *database.Repositories,
 							storer storage.Storer, db *database.DB, shutdowner fx.Shutdowner) *RestoreApp {
@@ -113,7 +111,7 @@ The age_secret_key must be configured in the config file for decryption.`,
 func (app *RestoreApp) runRestore(ctx context.Context, snapshotID string, opts *RestoreOptions) error {
 	// Check for age_secret_key
 	if app.Config.AgeSecretKey == "" {
-		return fmt.Errorf("age_secret_key missing from config - required for restore")
+		return fmt.Errorf("age_secret_key required for restore - set in config file or VAULTIK_AGE_SECRET_KEY environment variable")
 	}
 
 	log.Info("Starting restore operation",