Add watcher tests, refactor watch() to accept context

- Added watcher_test.go: 10 tests covering create, write, remove,
  rename, ignored files, debouncing, directory creation/removal,
  and manifest updates
- Refactored watch() to accept context.Context for clean cancellation
- Added signal handling (SIGINT/SIGTERM) for graceful shutdown in main.go
- Fixed test expectations (version two = 11 bytes, not 10)

1 files changed, 8 insertions, 1 deletions

diff --git a/main.go b/main.go
index 345436f..436c7b7 100644
--- a/main.go
+++ b/main.go
@@ -1,8 +1,12 @@
 package main
 
 import (
+	"context"
 	"flag"
 	"log"
+	"os"
+	"os/signal"
+	"syscall"
 )
 
 var (
@@ -31,7 +35,10 @@ func main() {
 		log.Fatalf("initial sync failed: %v", err)
 	}
 
-	if err := watch(*hostDir, *dataDir, manifest, rules, *dryRun, *verbose); err != nil {
+	ctx, cancel := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
+	defer cancel()
+
+	if err := watch(ctx, *hostDir, *dataDir, manifest, rules, *dryRun, *verbose); err != nil {
 		log.Fatalf("watcher failed: %v", err)
 	}
 }